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Nootan solutions for Chemistry Part 1 and 2 [English] Class 12 ISC chapter 3 - Electrochemistry [Latest edition]

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Chapters

Physical Chemistry

    1: Solid State

    2: Solutions

▶ 3: Electrochemistry

    4: Chemical Kinetics

    5: Surface Chemistry

Inorganic Chemistry

    6: General Principles and Processes of Isolation of Elements

    7: p-Block Elements

    8: d-and ƒ-Block Elements

    9: Coordination Compounds

Organic Chemistry

    10: Haloalkanes and Haloarenes

   Chapter 11: Alcohols, Phenols and Ethers

   Chapter 12: Aldehydes, Ketones and Carboxylic Acids

   Chapter 13: Organic Compounds containing Nitrogen

   Chapter 14: Biomolecules

    15: Polymers

   Chapter 16: Chemistry in Everyday Life

Nootan solutions for Chemistry Part 1 and 2 [English] Class 12 ISC chapter 3 - Electrochemistry - Shaalaa.com
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Solutions for Chapter 3: Electrochemistry

Below listed, you can find solutions for Chapter 3 of CISCE Nootan for Chemistry Part 1 and 2 [English] Class 12 ISC.


REVIEW EXERCISESVERY SHORT ANSWER TYPE QUESTIONSSHORT ANSWER TYPE QUESTIONSLONG ANSWER TYPE QUESTIONSINTEGER TYPE QUESTIONSOBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONSFILL IN THE BLANKS TYPE QUESTIONSASSERTION-REASON TYPE QUESTIONSNUMERICAL PROBLEMS'NCERT TEXT-BOOK' ExercisesQUESTIONS FROM ISC EXAMINATION PAPERS
REVIEW EXERCISES [Pages 148 - 187]

Nootan solutions for Chemistry Part 1 and 2 [English] Class 12 ISC 3 Electrochemistry REVIEW EXERCISES [Pages 148 - 187]

REVIEW EXERCISES | Q 3.1 | Page 148

Define a galvanic cell.

REVIEW EXERCISES | Q 3.2 (i) | Page 148

Define reference electrode.

REVIEW EXERCISES | Q 3.2 (ii) | Page 148

Define standard electrode potential.

REVIEW EXERCISES | Q 3.3 i. | Page 148

What is understood by a normal hydrogen electrode?

REVIEW EXERCISES | Q 3.3 ii. | Page 148

Give the significance of the normal hydrogen electrode.

REVIEW EXERCISES | Q 3.4 | Page 148

Define standard electrode potential.

REVIEW EXERCISES | Q 3.5 i. | Page 148

What do you understand by electrochemical series?

REVIEW EXERCISES | Q 3.5 ii. | Page 148

How does the electrochemical series help in predicting whether a given reaction is feasible in a given direction or not?

REVIEW EXERCISES | Q 3.6 | Page 148

It is impossible to measure the potential of a single electrode. Comment.

REVIEW EXERCISES | Q 3.7 i. | Page 148

What is standard hydrogen electrode?

REVIEW EXERCISES | Q 3.7 ii. | Page 148

Give the reaction that occurs at standard hydrogen electrode when it acts as positive electrode in an electrochemical cell.

REVIEW EXERCISES | Q 3.8 (a) | Page 148

What is the effect of change in concentration on the electrode potential of a given half-cell?

REVIEW EXERCISES | Q 3.8 (b) | Page 148

What is the effect of change in temperature on the electrode potential of a given half cell?

REVIEW EXERCISES | Q 3.9 | Page 148

Write the Nernst equation and explain the terms involved.

REVIEW EXERCISES | Q 3.10 | Page 148

State the values of `E_(Ca//Ca^(2+))^circ, E_(Ni//Ni^(2+))^circ` and `E_(Cl^-//1/2Cl_2)^circ` if  `E_(Ca^(2+)//Ca)^circ` = −2.87 volts, `E_(Ni^(2+)//Ni)^circ` = −0.25 volts and `E_(1/2Cl_2//Cl^-)^circ` = +1.36 volts.

REVIEW EXERCISES | Q 3.11 | Page 148

A potential difference of 0.25 volts is observed when an electrode system M/M2+ (1 mol L−1) is connected to a standard hydrogen electrode. If the direction of the flow of current is from hydrogen electrode to the metal electrode, calculate the standard potential of the electrode.

REVIEW EXERCISES | Q 3.12 | Page 148

The standard reduction potential of the electrode X/X+ (1 mol L−1) is +0.80 volts. Predict the direction of the flow of electrons when it is connected to a standard hydrogen electrode.

REVIEW EXERCISES | Q 3.13 | Page 148

Predict whether the following reaction is feasible under standard conditions or not: 

\[\ce{Zn_{(s)} + Cu{^{2+}_{(aq)}} -> Zn{^{2+}_{(aq)}} + Cu_{(s)}}\]

Given that `E_(Zn^(2+)//Zn)^circ` = −0.76 volts and `E_(Cu^(2+)//Cu)^circ` = +0.34 volts.

REVIEW EXERCISES | Q 3.14 (a) | Page 148

On the basis of electrochemical series, explain why Fe can displace hydrogen from dilute HCl but silver cannot.

REVIEW EXERCISES | Q 3.14 (b) | Page 148

On the basis of electrochemical series, explain why HCl cannot be stored in an aluminium vessel.

REVIEW EXERCISES | Q 3.14 (c) | Page 148

On the basis of electrochemical series, explain why Au2O3 decomposes on heating.

REVIEW EXERCISES | Q 3.14 (d) | Page 148

On the basis of electrochemical series, explain why a coating of copper is deposited on an iron nail when placed in an aqueous solution of copper sulphate.

REVIEW EXERCISES | Q 3.15 (a) | Page 148

Can we store copper sulphate solution in zinc vessel? Give suitable explanation. 

Given: \[\ce{E_{Cu^{2+}/Cu}}\] = +0.34 V, \[\ce{E_{Zn^{2+}/Zn}}\] = −0.76 V, \[\ce{E_{Ag^{+}/Ag}}\] = +0.80 V

REVIEW EXERCISES | Q 3.15 (b) | Page 148

Can we store copper sulphate solution in silver vessel? Give suitable explanation. 

Given: \[\ce{E{^{\circ}_{Cu^{2+}/Cu}}}\] = +0.34 V, \[\ce{E{^{\circ}_{Zn^{2+}/Zn}}}\] = −0.76 V, \[\ce{E{^{\circ}_{Ag^{+}/Ag}}}\] = +0.80 V.

REVIEW EXERCISES | Q 3.16 | Page 148

The two half cell reactions and their oxidation potentials are

  1. \[\ce{Pb_{(s)} - 2e- -> Pb{^{2+}_{(aq)}}, E^{\circ}_{Pb/Pb^{2+}}}\] = +0.13 V
  2. \[\ce{Ag_{(s)} - e- -> Ag{^+_{(aq)}}, E^{\circ}_{Ag/Ag^{+}}}\] = −0.80 V

Write the cell reaction and calculate the cell emf.

REVIEW EXERCISES | Q 3.17 | Page 148

A cell is prepared by dipping a copper rod in 1 M copper sulphate solution and a zinc rod in 1 M zinc sulphate solution. The standard reduction potentials of copper and zinc are 0.34 V and −0.76 V respectively.

  1. What will be the cell reaction?
  2. What will be the standard emf of the cell?
  3. Which electrode will be positive?
  4. How can the cell be represented?
REVIEW EXERCISES | Q 3.18 | Page 149

Calculate at 25°C the electrode potential of Mg2+/Mg electrode in which the concentration of Mg2+ ions is 0.1 M. Given \[\ce{E^{\circ}_{Mg^{2+}/Mg}}\] = −2.36 V, R = 8.314 JK−1, F = 96500 coulombs mol−1.

REVIEW EXERCISES | Q 3.19 | Page 149

Why does the blue colour of copper sulphate solution get discharged when zinc rod is dipped into it?

Given: \[\ce{E^{\circ}_{Cu^{2+}/Cu}}\] = +0.34 V and \[\ce{E^{\circ}_{Zn^{2+}/Zn}}\] = −0.76 V.

REVIEW EXERCISES | Q 3.20 (a) | Page 149

Using the standard electrode potentials, predict if the reaction between the following is feasible:

\[\ce{Fe^{3+}_{ (aq)}}\] and \[\ce{I^-_{ (aq)}}\]

REVIEW EXERCISES | Q 3.20 (b) | Page 149

Using the standard electrode potentials, predict if the reaction between the following is feasible:

\[\ce{Ag^+_{ (aq)}}\] and Cu(s)

REVIEW EXERCISES | Q 3.20 (c) | Page 149

Using the standard electrode potentials, predict if the reaction between the following is feasible:

\[\ce{Fe^{3+}_{ (aq)}}\] and \[\ce{Br^-_{ (aq)}}\]

REVIEW EXERCISES | Q 3.20 (d) | Page 149

Using the standard electrode potential, predict if the reaction between the following is feasible:

Ag(s) and \[\ce{Fe^{3+}_{ (aq)}}\]

REVIEW EXERCISES | Q 3.20 (e) | Page 149

Using the standard electrode potential, predict if the reaction between the following is feasible:

Br2(aq) and \[\ce{Fe^{2+}_{ (aq)}}\]

REVIEW EXERCISES | Q 3.21 (i) | Page 149

Calculate the electrode potentials of the following half cell at 25°C. 

Pt, Cl2 (10 atm) | HCl (0.1 M)

Given: \[\ce{E^{\circ}_{\frac{1}{2}Cl_2/Cl^-}}\] = +1.36 V and \[\ce{E{^{\circ}_{H^+/\frac{1}{2}H_2}}}\] = 0.00 V.

REVIEW EXERCISES | Q 3.21 (ii) | Page 149

Calculate the electrode potentials of the following half cell at 25°C.

Pt, H2 (5 atm) | HCl (0.5 M)

Given: \[\ce{E^{\circ}_{\frac{1}{2}Cl_2/Cl^-}}\] = +1.36 V and \[\ce{E{^{\circ}_{H^+/\frac{1}{2}H_2}}}\] = 0.00 V.

REVIEW EXERCISES | Q 3.22 (a) | Page 149

Calculate the electrode potentials of the following half cells at 298 K.

Ag(s) | AgNO3 (0.1 M)

Given: \[\ce{E^{\circ}_{Ag^+/Ag}}\] = +0.80 V, \[\ce{E^{\circ}_{{Co^{2+}/Co}}}\] = −0.28 V

REVIEW EXERCISES | Q 3.22 (b) | Page 149

Calculate the electrode potentials of the following half cells at 298 K.

Co(s) | Co2+ (0.01 M)

Given: \[\ce{E^{\circ}_{Ag^+/Ag}}\] = +0.80 V, \[\ce{E^{\circ}_{{Co^{2+}/Co}}}\] = −0.28 V

REVIEW EXERCISES | Q 3.23 | Page 156

Write Nernst equation for the following cell reaction:

\[\ce{2 A + 3 B -> C + 2 D}\]

REVIEW EXERCISES | Q 3.24 | Page 156

How can the cell potential be used in predicting the feasibility of a cell reaction?

REVIEW EXERCISES | Q 3.25 | Page 156

Calculate the EMF of the cell at 298 K:

Pt, Br2 | Br(0.01 M) || H+ (0.03 M) | H2 (1 atm), Pt

Given: \[\ce{E^{\circ}_{\frac{1}{2}Br/Br^-}}\] = +1.08 V.

REVIEW EXERCISES | Q 3.26 | Page 156

Calculate the standard electrode potential of the Ni2+/Ni electrode, if the cell potential of the cell is 0.59 V.

Ni | Ni2+ (0.01 M) || Cu2+ (0.1 M) | Cu

Given: \[\ce{E^{\circ}_{Cu{^{2+}/Cu}}}\] = +0.34 V

REVIEW EXERCISES | Q 3.27 | Page 156

Calculate the emf of the following cell at 298 K:

Mg | Mg2+ (0.001 M) || Cu2+ (0.0001 M) | Cu

Given: \[\ce{E^{\circ}_{{Cu^{2+}/{Cu}}}}\] = 0.337 V, \[\ce{E^{\circ}_{{Mg^{2+}/{Mg}}}}\] = −2.37 V, F = 96500 C mol−1.

REVIEW EXERCISES | Q 3.28 | Page 156

Calculate the EMF of the following cell at 298 K:

Mg | Mg2+ (0.1 M) || Ag+ (0.1 M) | Ag

\[\ce{E^{\circ}_{{Mg^{2+}/{Mg}}}}\] = −2.37 V, \[\ce{E^{\circ}_{{Ag^{+}/{Ag}}}}\] = +0.80 V, R = 8.31 J K−1, F = 96500 C mol−1.

REVIEW EXERCISES | Q 3.29 | Page 157

Consider a cell composed of two half cells:

  1. \[\ce{Cu_{(s)} | Cu{^{2+}_{(aq)}}}\] and
  2. \[\ce{Ag_{(s)} | Ag{^+_{(aq)}}}\].

Calculate: (a) the standard cell potential, and (b) the cell potential when [Cu2+] is 2M and [Ag+] is 0.05 M.

Given: \[\ce{E^{\circ}_{{Cu^{2+}/{Cu}}}}\] = +0.33 V, \[\ce{E^{\circ}_{{Ag^{+}/{Ag}}}}\] = +0.80 V, R = 8.31 J K−1 mol−1, F = 96500 C mol−1.

REVIEW EXERCISES | Q 3.30 | Page 127

Consider a cell composed of the following two half cells:

  1. \[\ce{Mg_{(s)} | Mg{^{2+}_{(aq)}}}\], and
  2. \[\ce{Ag_{(s)} | Ag{^{+}_{(aq)}}}\]

The EMF of the cell is 2.96 V, [Mg2+] = 0.130 M and [Ag+] = 1.0 × 10−4 M. Calculate the standard EMF of the cell. (R = 8.31 J K−1 mol−1, F = 96500 C mol−1)

REVIEW EXERCISES | Q 3.31 | Page 157

Calculate the cell potential at 298 K: 

\[\ce{Zn_{(s)} | Zn^{2+} (0.1 M) || Sn^{2+} (0.001 M) | Sn_{(s)}}\]

(Given: \[\ce{E{^{\circ}_{Zn^{2+}/Zn}}}\] = −0.76 V, \[\ce{E{^{\circ}_{Sn^{2+}/Sn}}}\] = −0.14 V, Gas constant, R = 8.314 J K−1 mol−1, Faraday constant, F = 96500 C mol−1)

REVIEW EXERCISES | Q 3.32 | Page 157

The standard potentials are given as: 

\[\ce{E{^{\circ}_{Cu^{2+}/Cu}}}\] = +0.34 V, and \[\ce{E{^{\circ}_{Ag^{+}/Ag}}}\] = +0.80 V.

Calculate the cell potential (E) for the cell containing 0.100 M Ag+ and 4.00 M Cu2+ at 298 K.

REVIEW EXERCISES | Q 3.33 | Page 157

Predict whether the following reaction will occur spontaneously at 298 K: 

\[\ce{Co_{(s)} + Fe{^{2+}_{(aq)}} -> Co{^{2+}_{(aq)}} + Fe_{(s)}}\]

Given: \[\ce{E^{\circ}_{{Co^{2+}/{Co}}}}\] = −0.28 V and \[\ce{E^{\circ}_{{Fe^{2+}/{Fe}}}}\] = −0.44 V.

REVIEW EXERCISES | Q 3.34 | Page 157

The half reactions are:

  1. \[\ce{Fe^3+ + e- -> Fe^2+}\]; E° = 0.76 V
  2. \[\ce{Ag+ + e- -> Ag}\]; E° = 0.80 V

Calculate Kc for the following reaction at 25°C:

\[\ce{Ag+ + Fe^2+ -> Fe^3+ + Ag}\] (F = 96500 C mol−1)

REVIEW EXERCISES | Q 3.35 | Page 157

Calculate the emf of the cell:

Mg(s) | Mg2+ (0.1 M) || Cu2+ (1 × 10−3 M) | Cu(s)

Given \[\ce{E^{\circ}_{{Cu^{2+}/{Cu}}}}\] = +0.34 V, \[\ce{E^{\circ}_{{Mg^{2+}/{Mg}}}}\] = −2.37 V

REVIEW EXERCISES | Q 3.36 | Page 165

What are electrolytic conductors?

REVIEW EXERCISES | Q 3.37 (i) | Page 165

Define the following term:

Specific conductance

REVIEW EXERCISES | Q 3.37 (ii) | Page 165

Define the term equivalent conductance.

REVIEW EXERCISES | Q 3.38 (i) | Page 165

Define the term cell constant.

REVIEW EXERCISES | Q 3.38 (ii) | Page 165

Define “Molar conductivity”.

REVIEW EXERCISES | Q 3.39 | Page 165

What is the SI unit of molar conductivity?

REVIEW EXERCISES | Q 3.40 i. | Page 165

Define “Molar conductivity”.

REVIEW EXERCISES | Q 3.40 ii. | Page 165

Mention the effect of temperature on molar conductivity.

REVIEW EXERCISES | Q 3.41 i. | Page 165

Define the term equivalent conductance.

REVIEW EXERCISES | Q 3.41 ii. | Page 165

Define “Molar conductivity”.

REVIEW EXERCISES | Q 3.41 iii. | Page 165

What are the physical significances of equivalent conductivity?

REVIEW EXERCISES | Q 3.41 iv. | Page 165
What are the physical significances of molar conductivity?
REVIEW EXERCISES | Q 3.42 | Page 165

The resistance of 0.01 M NaCl solution in a conductivity cell was found to be 210 Ω. The specific conductance of this solution is 4.5 × 10−3 S cm−1. What is the cell constant of the cell?

REVIEW EXERCISES | Q 3.43 | Page 157

The resistance of 0.01 N NaCl solution is 200 Ω at 25°C. Cell constant of the conductivity cell is unity. Calculate the equivalent conductance of the solution.

REVIEW EXERCISES | Q 3.44 | Page 165

The specific conductance of `N/50` solution of KCl at 25°C is 0.002765 mho cm−1. If the resistance of a cell containing this solution is 400 ohms, find out the cell constant.

REVIEW EXERCISES | Q 3.45 | Page 165

Calculate the equivalent conductance of 1 M H2SO4 solution, if its conductivity is 2.6 × 10−2 ohm−1 cm−1.

REVIEW EXERCISES | Q 3.46 | Page 165

The resistance of a decinormal solution of a salt occupying a volume between two platinum electrodes 1.80 cm apart and 5.4 cm2 in area was found to be 32 ohms.

Calculate the specific and equivalent conductances of the solution.

REVIEW EXERCISES | Q 3.47 | Page 165

A conductivity cell has its electrodes 1 cm apart and each electrode has a cross section of 2 cm2. When filled with `N/50` solution of an electrolyte MX, the cell shows a resistance of 166.5 ohms. Calculate the equivalent conductivity of MX at the given concentration.

REVIEW EXERCISES | Q 3.48 | Page 165

A potential difference of 20 volts applied to the ends of a column of `N/10` AgNO3 solution, 4 cm in diameter and 12 cm in length, gives a current of 1.198 amperes. Calculate the specific and equivalent conductivity of the solution.

REVIEW EXERCISES | Q 3.49 | Page 166

A conductivity cell when filled with 0.05 M solution of KCl records a resistance of 410.5 ohm at 25°C. When filled with CaCl2 solution (11 g in 500 mL), it records a resistance of 990 ohms. If specific conductance of 0.05 M KCl is 0.00189 ohm−1 cm−1, calculate

  1. cell constant; 
  2. specific conductance of CaCl2;
  3. equivalent conductance of CaCl2 solution;
  4. molar conductance of CaCl2 solution.
REVIEW EXERCISES | Q 3.50 | Page 166

A cell with N/50 KCl solution showed a resistance of 550 ohms at 25°C. The specific conductivity of N/50 KCl at 25°C is 0.002768 ohm−1,cm−1. The cell filled with N/10 ZnSO4 solution at 25°C shows a resistance of 72.18 ohms. Calculate the cell constant and molar conductivity of ZnSO4 solution.

REVIEW EXERCISES | Q 3.51 | Page 171

How does molar conductance of a strong electrolyte vary with its concentration in solution?

REVIEW EXERCISES | Q 3.52 | Page 171

How does molar conductivity of a weak electrolyte vary with its concentration in solution?

REVIEW EXERCISES | Q 3.53 | Page 171

What is the effect of decreasing concentration on the molar conductivity of a weak electrolyte?

REVIEW EXERCISES | Q 3.54 | Page 171

State and explain Kohlrausch’s law.

REVIEW EXERCISES | Q 3.55 | Page 171

How can the degree of dissociation of acetic acid be calculated from its molar conductance data?

REVIEW EXERCISES | Q 3.56 | Page 171

At 298 K, the molar conductivities at infinite dilution of sodium propionate (CH3CH2COONa), HCl and NaCl are 85.9, 426.1 and 126 ohm−1 cm2 mol−1 respectively. Calculate the molar conductivity of propionic acid at infinite dilution.

REVIEW EXERCISES | Q 3.57 | Page 171

The molar conductivity of a weak monobasic acid at infinite dilution is 387 ohm−1 cm2 mol−1. The 0.02 M solution of the same acid has a specific conductivity of 3.3 × 10−4 ohm−1 cm2 mol−1. Calculate the degree of dissociation of the acid at the given concentration.

REVIEW EXERCISES | Q 3.58 | Page 171

The molar conductivity of CH3COOH at infinite dilution is found to be 387 ohm−1 cm2 mol−1 but at a dilution of 1 g mol in 1000 litres it is 55 ohm−1 cm2 mol−1. What is the percent dissociation of the acid at the given dilution?

REVIEW EXERCISES | Q 3.59 | Page 171

Calculate the molar conductivity at infinite dilution for CH3COOH if the molar conductivity at infinite dilution for NaCl, HCl and CH3COONa are 126.45, 426.16 and 91.0 ohm−1 cm2 mol−1 respectively.

REVIEW EXERCISES | Q 3.60 | Page 171

The molar conductance at infinite dilution of Al2(SO4)3 is 858 ohm−1 cm2 mol−1. Calculate the molar conductance at infinite dilution of Al3+ ion if that of \[\ce{SO^{2-}_{4}}\] ion is 160 ohm−1 cm2 mol−1.

REVIEW EXERCISES | Q 3.61 i. | Page 179

What is electrolysis?

REVIEW EXERCISES | Q 3.61 ii. | Page 179

Explain the mechanism of electrolysis by taking a suitable example.

REVIEW EXERCISES | Q 3.62 (i) | Page 179

Define the following term:

Faraday

REVIEW EXERCISES | Q 3.62 (ii) | Page 179

Define the following term:

Electrochemical equivalent

REVIEW EXERCISES | Q 3.63 | Page 179

Explain the criteria for product formation during electrolysis taking the example of aqueous sodium chloride.

REVIEW EXERCISES | Q 3.64 | Page 179

State Faraday’s Laws of electrolysis.

REVIEW EXERCISES | Q 3.65 | Page 179

Predict the products of electrolysis of an aqueous solution of CuBr2 using inert electrodes.

Given: \[\ce{E^{\circ}_{{Cu^{2+}/{Cu}}}}\] = 0.34 V, \[\ce{E^{\circ}_{{H_{2}O}/H_{2}}}\], OH = −0.83 V, \[\ce{E^\circ_{Br/Br^-}}\] = 1.08 V and \[\ce{E^{\circ}_{\frac{1}{2} O_{2}, H{^{+}}/{H_{2}O}}}\] = 1.23 V.

REVIEW EXERCISES | Q 3.66 (i) | Page 179

How many coulombs of electricity are required for reduction of 1 mole of \[\ce{Cr2O^{2-}_{ 7}}\] to Cr3+?

REVIEW EXERCISES | Q 3.66 (ii) | Page 179

How much electricity is required in coulomb for the oxidation of 1 mol of H2O to O2?

REVIEW EXERCISES | Q 3.66 (iii) | Page 179

How many coulombs of electricity are required for reduction of 1 mole of Sn4+ to Sn2+?

REVIEW EXERCISES | Q 3.67 | Page 179

Calculate the number of coulombs required to deposit 5.4 g of Al when the electrode reaction is Al3 + 3e + Al.
(Given: Atomic mass of Al = 27 g mol−1, F = 96500 C mol−1)

REVIEW EXERCISES | Q 3.68 | Page 179

Calculate the quantity of electricity that would be required to reduce 12.3 g of nitrobenzene to aniline, if the current efficiency is 50%.

REVIEW EXERCISES | Q 3.69 | Page 180

How many molecules of chlorine should be deposited from sodium chloride in 1 minute by a current of 300 mA?

REVIEW EXERCISES | Q 3.70 | Page 180

A constant current was passed through a solution of \[\ce{AuCl^-_4}\] between gold electrodes. After a period of 14 minutes, the cathode recorded an increase in mass of 1.808 g. Calculate the quantity of current passed in solution. What was the magnitude of current? (Atomic mass of gold = 197.0)

REVIEW EXERCISES | Q 3.71 | Page 180

A current of 4 amperes was passed for 2 hours through a solution of copper sulphate when 5.0 g of copper was deposited. Calculate the current efficiency.

REVIEW EXERCISES | Q 3.72 | Page 180

Two voltameters containing CuSO4 and acidulated water respectively are connected in series and the same current is passed for some time. 0.3177 g copper is deposited in the first one. Calculate the weight of liberated hydrogen in the second. (At. wt. of Cu = 63.5 and H = 1.008)

REVIEW EXERCISES | Q 3.73 | Page 180

An aqueous solution of NaCl on electrolysis gives H2(g), Cl2(g) and NaOH according to the reaction

\[\ce{2Cl^-_{ (aq)} + 2H2O -> 2OH^-_{ (aq)} + H2_{(g)} + Cl2_{(g)}}\].

A direct current of 25 amperes with a current efficiency of 62% is passed through 20 litres of NaCl solution (20% by weight).

  1. Write down the reactions taking place at the electrodes.
  2. How long will it take to produce 1 kg of Cl2?
  3. What will be the molarity of solution with respect to OH? Assume no loss in volume due to evaporation.
REVIEW EXERCISES | Q 3.74 | Page 180

Explain, why electrolysis of aqueous solution of NaCl gives H2 at cathode and Cl2 at anode. Write overall reaction.

[Given: \[\ce{E^{\circ}_{{Na^{+}/{Na}}}}\] = 2.71 V, \[\ce{E^{\circ}_{Cl_2/2Cl^-}}\] = 1.36 V and \[\ce{\frac{1}{2} O2_{(g)} + 2H+_{ (aq)} + 2e- -> H2O_{(l)}}\]; E° = 1.23 V]

REVIEW EXERCISES | Q 3.75 | Page 180

Silver is electrodeposited on a metallic vessel of surface area 800 cm2 by passing current of 0.2 amp for 3 hours. Calculate the thickness of silver deposited. 

(Density of silver = 10.47 g cm−3, atomic mass of silver = 107.92 amu)

REVIEW EXERCISES | Q 3.76 (i) | Page 180

Predict the products of electrolysis obtained at the electrodes in the case when the electrodes used are of platinum:

An aqueous solution of AgNO3.

REVIEW EXERCISES | Q 3.76 (ii) | Page 180

Predict the product of electrolysis in the following:

A dilute solution of H2SO4 with platinum electrodes.

REVIEW EXERCISES | Q 3.77 | Page 180

How much charge is required for the following reduction? 

1 mol of Cu2+ to Cu.

REVIEW EXERCISES | Q 3.78 i. | Page 187

What is a primary cell?

REVIEW EXERCISES | Q 3.78 ii. | Page 187

What is a secondary cell? 

REVIEW EXERCISES | Q 3.78 iii. | Page 187

Write the differences between the primary cell and the secondary cell.

REVIEW EXERCISES | Q 3.79 i. | Page 187

What do you understand by the term fuel-cell?

REVIEW EXERCISES | Q 3.79 ii. | Page 187

Give electrode reactions of hydrogen-oxygen fuel cell.

REVIEW EXERCISES | Q 3.80 i. | Page 187

What is a mercury cell?

REVIEW EXERCISES | Q 3.80 ii. | Page 187

Give the electrode reactions of the mercury cell.

REVIEW EXERCISES | Q 3.81 i. | Page 187

What is corrosion?

REVIEW EXERCISES | Q 3.81 ii. | Page 187

Give a brief account of the mechanism of corrosion.

REVIEW EXERCISES | Q 3.82 i. | Page 187

What is corrosion?

REVIEW EXERCISES | Q 3.82 ii. | Page 187

How is the cathodic protection of iron different from its galvanisation?

REVIEW EXERCISES | Q 3.83 i. | Page 187

What is galvanisation?

REVIEW EXERCISES | Q 3.83 ii. | Page 187

In what respect is galvanisation better than tin coating used for the protection of iron from corrosion?

REVIEW EXERCISES | Q 3.84 i. | Page 187

Write two applications of fuel cells.

REVIEW EXERCISES | Q 3.84 ii. | Page 187

Describe the limitations of fuel cells.

REVIEW EXERCISES | Q 3.85 | Page 187

Explain why tin protects copper more efficiently as compared to iron?

REVIEW EXERCISES | Q 3.86 | Page 187

Discuss the factors which govern the rate of corrosion of a metal.

REVIEW EXERCISES | Q 3.87 | Page 187

Give a brief account of the mechanism of corrosion.

REVIEW EXERCISES | Q 3.88 | Page 187

Give an example of a fuel cell and write the anode and cathode reactions for it.

REVIEW EXERCISES | Q 3.89 | Page 187

How does a fuel cell operate?

REVIEW EXERCISES | Q 3.90 (i) | Page 187

Write the cell reactions which occur in lead storage battery when the battery is in use.

REVIEW EXERCISES | Q 3.90 (ii) | Page 187

Write the cell reactions which occur in a lead storage battery when the battery is on charging.

VERY SHORT ANSWER TYPE QUESTIONS [Pages 192 - 193]

Nootan solutions for Chemistry Part 1 and 2 [English] Class 12 ISC 3 Electrochemistry VERY SHORT ANSWER TYPE QUESTIONS [Pages 192 - 193]

VERY SHORT ANSWER TYPE QUESTIONS | Q 1. | Page 192

Differentiate between conductors and insulators.

VERY SHORT ANSWER TYPE QUESTIONS | Q 2. | Page 192

What do you understand by non-electrolytes?

VERY SHORT ANSWER TYPE QUESTIONS | Q 3. | Page 192

What is the effect of temperature on metallic conduction?

VERY SHORT ANSWER TYPE QUESTIONS | Q 4. | Page 192

What type of species are responsible for electrolytic conduction?

VERY SHORT ANSWER TYPE QUESTIONS | Q 5. | Page 192

Can electric current be passed through a solid ionic compound?

VERY SHORT ANSWER TYPE QUESTIONS | Q 6. | Page 192

How does electrolytic conduction vary with temperature?

VERY SHORT ANSWER TYPE QUESTIONS | Q 7. i. | Page 192

What is meant by the term ‘electrolyte’?

VERY SHORT ANSWER TYPE QUESTIONS | Q 7. ii. | Page 192

Give two examples of electrolytes.

VERY SHORT ANSWER TYPE QUESTIONS | Q 8. | Page 192

Distinguish between strong electrolyte and weak electrolyte.

VERY SHORT ANSWER TYPE QUESTIONS | Q 9. | Page 192

Define the degree of dissociation.

VERY SHORT ANSWER TYPE QUESTIONS | Q 10. | Page 192

How does solute-solute interaction affect electrolytic conduction?

VERY SHORT ANSWER TYPE QUESTIONS | Q 11. | Page 192

What is the effect of solute-solvent interaction on electrolytic conduction?

VERY SHORT ANSWER TYPE QUESTIONS | Q 12. | Page 192

State Ostwald’s dilution law.

VERY SHORT ANSWER TYPE QUESTIONS | Q 13. | Page 192

Define the following term:

Specific conductance

VERY SHORT ANSWER TYPE QUESTIONS | Q 14. | Page 192

What are the units of specific conductivity?

VERY SHORT ANSWER TYPE QUESTIONS | Q 15. | Page 192

How is equivalent conductivity related to specific conductivity?

VERY SHORT ANSWER TYPE QUESTIONS | Q 16. i. | Page 192

Define the term equivalent conductance.

VERY SHORT ANSWER TYPE QUESTIONS | Q 16. ii. | Page 192

Mention the units of equivalent conductivity.

VERY SHORT ANSWER TYPE QUESTIONS | Q 17. | Page 192

What is the relationship between molar conductivity and specific conductivity?

VERY SHORT ANSWER TYPE QUESTIONS | Q 18. i. | Page 192

Define “Molar conductivity”.

VERY SHORT ANSWER TYPE QUESTIONS | Q 18. ii. | Page 192

What is the SI unit of molar conductivity?

VERY SHORT ANSWER TYPE QUESTIONS | Q 19. | Page 192

What is cell constant?

VERY SHORT ANSWER TYPE QUESTIONS | Q 20. | Page 192

Define molar conductivity at infinite dilution.

VERY SHORT ANSWER TYPE QUESTIONS | Q 21. | Page 192

Why is the molar conductivity of a weak electrolyte much lower than that of a strong electrolyte at moderate concentrations?

VERY SHORT ANSWER TYPE QUESTIONS | Q 22. i. | Page 192

What is specific resistance?

VERY SHORT ANSWER TYPE QUESTIONS | Q 22. ii. | Page 192
What are the SI units of specific resistance?
VERY SHORT ANSWER TYPE QUESTIONS | Q 23. | Page 192

How would you represent a Daniell cell?

VERY SHORT ANSWER TYPE QUESTIONS | Q 24. | Page 192

What is the polarity of anode in a galvanic cell and why?

VERY SHORT ANSWER TYPE QUESTIONS | Q 25. | Page 192

What do you understand by a half cell?

VERY SHORT ANSWER TYPE QUESTIONS | Q 26. | Page 192

How would you represent a half cell in which H+ ions of conc. 0.2 M get reduced into hydrogen gas at atmospheric pressure?

VERY SHORT ANSWER TYPE QUESTIONS | Q 27. | Page 192

What is the direction of flow of electrons in the outer circuit in a galvanic cell?

VERY SHORT ANSWER TYPE QUESTIONS | Q 28. | Page 192

Define electrode potential.

VERY SHORT ANSWER TYPE QUESTIONS | Q 29. | Page 192

What is a null electrode?

VERY SHORT ANSWER TYPE QUESTIONS | Q 30. | Page 192

Name the electrode and the potential when the electrode reaction involves reduction.

VERY SHORT ANSWER TYPE QUESTIONS | Q 31. | Page 192

What do you understand by standard electrode potential?

VERY SHORT ANSWER TYPE QUESTIONS | Q 32. | Page 192

What is the reference electrode generally used in the measurement of standard electrode potential of an electrode assembly?

VERY SHORT ANSWER TYPE QUESTIONS | Q 33. | Page 192

What is the function of platinised platinum in the standard hydrogen electrode?

VERY SHORT ANSWER TYPE QUESTIONS | Q 34. | Page 192

Represent a standard hydrogen electrode.

VERY SHORT ANSWER TYPE QUESTIONS | Q 35. | Page 192

What is the direction of flow of electrons in the outer circuit when a standard hydrogen electrode is connected to a copper electrode?

VERY SHORT ANSWER TYPE QUESTIONS | Q 36. | Page 192

How does the tendency to gain electrons vary when one moves from the top to the bottom in the electrochemical series?

VERY SHORT ANSWER TYPE QUESTIONS | Q 37. | Page 193

It is impossible to measure the potential of a single electrode. Comment.

VERY SHORT ANSWER TYPE QUESTIONS | Q 38. | Page 193

Predict whether F2 and Na will react together:

\[\ce{E^{\circ}_{F/F^-}}\] = +2.87 V, \[\ce{E^{\circ}_{{Na^{+}/{Na}}}}\] = −2.71 V

VERY SHORT ANSWER TYPE QUESTIONS | Q 39. | Page 193

Which substance can be used to oxidise fluorides to fluorine?

VERY SHORT ANSWER TYPE QUESTIONS | Q 40. | Page 193

How does the reducing power of elements vary on moving down the electrochemical series?

VERY SHORT ANSWER TYPE QUESTIONS | Q 41. | Page 193

Can copper displace zinc from its salt solution?

\[\ce{E^{\circ}_{{Zn^{2+}/{Zn}}}}\] = −0.76 V, \[\ce{E^{\circ}_{{Cu^{2+}/{Cu}}}}\] = +0.34 V

VERY SHORT ANSWER TYPE QUESTIONS | Q 42. | Page 193

Can nickel displace hydrogen from hydrochloric acid?

\[\ce{E^{\circ}_{{Ni^{2+}/{Ni}}}}\] = −0.25 V

VERY SHORT ANSWER TYPE QUESTIONS | Q 43. | Page 193

Write the Nernst equation for a reduction electrode.

VERY SHORT ANSWER TYPE QUESTIONS | Q 44. | Page 193

Define emf of a galvanic cell.

VERY SHORT ANSWER TYPE QUESTIONS | Q 45. | Page 193

What is the convention for the emf of a cell?

VERY SHORT ANSWER TYPE QUESTIONS | Q 46. | Page 193

Mention the relationship between the standard cell potential and standard electrode potentials of the two electrodes.

VERY SHORT ANSWER TYPE QUESTIONS | Q 47. | Page 193

Write the Nernst equation for a cell having the cell reaction. 

\[\ce{aA + bB -> cC + dD}\].

VERY SHORT ANSWER TYPE QUESTIONS | Q 48. | Page 193

The standard reduction potential for \[\ce{Zn{^{2+}_{(aq)}} | Zn_{(s)}}\] half cell is −0.76 V. Write the reactions occurring at the electrodes when coupled with NHE.

VERY SHORT ANSWER TYPE QUESTIONS | Q 49. | Page 193

Define electrolysis.

VERY SHORT ANSWER TYPE QUESTIONS | Q 50. | Page 193

Why does an aqueous solution of sodium chloride on electrolysis give H2 at cathode instead of sodium?

VERY SHORT ANSWER TYPE QUESTIONS | Q 51. | Page 193

What is overvoltage?

VERY SHORT ANSWER TYPE QUESTIONS | Q 52. | Page 193

Why do Cl ions get oxidised at anode in preference to H2O during the electrolysis of an aqueous solution of sodium chloride?

VERY SHORT ANSWER TYPE QUESTIONS | Q 53. | Page 193

Predict the products of electrolysis of a dilute aqueous solution of sulphuric acid using inert electrodes.

VERY SHORT ANSWER TYPE QUESTIONS | Q 54. | Page 193

State Faraday’s Laws of electrolysis.

VERY SHORT ANSWER TYPE QUESTIONS | Q 55. i. | Page 193

What is electrochemical equivalent?

VERY SHORT ANSWER TYPE QUESTIONS | Q 55. ii. | Page 193

How can electrochemical equivalent be calculated for a particular substance?

VERY SHORT ANSWER TYPE QUESTIONS | Q 56. | Page 193

What is the quantity of electricity needed to liberate one equivalent of a substance?

VERY SHORT ANSWER TYPE QUESTIONS | Q 57. | Page 193

Calculate the electric charge carried by one electron on the basis of Faraday’s constant.

VERY SHORT ANSWER TYPE QUESTIONS | Q 58. | Page 193

How much charge is required to reduce 8 g of H+ ions to H2 gas?

VERY SHORT ANSWER TYPE QUESTIONS | Q 59. | Page 193

How can you increase the reduction potential of an electrode?

VERY SHORT ANSWER TYPE QUESTIONS | Q 60. | Page 193

Electrolysis of KBr(aq) gives Br2 at anode but that of KF(aq) does not give F2. Give reason.

SHORT ANSWER TYPE QUESTIONS [Pages 194 - 195]

Nootan solutions for Chemistry Part 1 and 2 [English] Class 12 ISC 3 Electrochemistry SHORT ANSWER TYPE QUESTIONS [Pages 194 - 195]

SHORT ANSWER TYPE QUESTIONS | Q 1. i. | Page 194

Define electrochemistry.

SHORT ANSWER TYPE QUESTIONS | Q 1. ii. | Page 194

Discuss the scope of electrochemistry.

SHORT ANSWER TYPE QUESTIONS | Q 2. i. | Page 194

What is metallic conduction?

SHORT ANSWER TYPE QUESTIONS | Q 2. ii. | Page 194

How does metallic conduction differ from electrolytic conduction?

SHORT ANSWER TYPE QUESTIONS | Q 3. | Page 194

Discuss the factors which affect electrolytic dissociation.

SHORT ANSWER TYPE QUESTIONS | Q 4. i. | Page 194

What is specific resistance?

SHORT ANSWER TYPE QUESTIONS | Q 4. ii. | Page 194
What do you mean by conductance of a conductor of a solution?
SHORT ANSWER TYPE QUESTIONS | Q 4. iii. | Page 194

What do you understand by specific conductance of a solution?

SHORT ANSWER TYPE QUESTIONS | Q 4. iv. | Page 194

Derive the units for specific resistance of a solution.

SHORT ANSWER TYPE QUESTIONS | Q 4. v. | Page 194

Derive the units for conductance of a solution.

SHORT ANSWER TYPE QUESTIONS | Q 4. vi. | Page 194

Derive the units of specific conductivities of an electrolytic solution and write expressions which show their mutual relationship.

SHORT ANSWER TYPE QUESTIONS | Q 5. i. | Page 194

Define the term equivalent conductance.

SHORT ANSWER TYPE QUESTIONS | Q 5. ii. | Page 194

How is equivalent conductivity related to specific conductivity?

SHORT ANSWER TYPE QUESTIONS | Q 5. iii. | Page 194

Derive the units of equivalent conductivity of a solution.

SHORT ANSWER TYPE QUESTIONS | Q 6. i. | Page 194

Define “Molar conductivity”.

SHORT ANSWER TYPE QUESTIONS | Q 6. ii. | Page 194

What is the SI unit of molar conductivity?

SHORT ANSWER TYPE QUESTIONS | Q 7. i. | Page 194

What is the relationship between molar conductivity and specific conductivity?

SHORT ANSWER TYPE QUESTIONS | Q 7. ii. | Page 194

Derive a relationship between molar conductivity and equivalent conductivity.

SHORT ANSWER TYPE QUESTIONS | Q 8. i. | Page 194

What is conductivity cell?

SHORT ANSWER TYPE QUESTIONS | Q 8. ii. | Page 194

For what purpose is a conductivity cell used?

SHORT ANSWER TYPE QUESTIONS | Q 9. i. | Page 194

What is wheatstone bridge?

SHORT ANSWER TYPE QUESTIONS | Q 9. ii. | Page 194

What is the wheatstone bridge’s significance in the determination of the conductivity of a solution?

SHORT ANSWER TYPE QUESTIONS | Q 10. i. | Page 194

What is cell constant?

SHORT ANSWER TYPE QUESTIONS | Q 10. ii. | Page 194

How is cell constant determined?

SHORT ANSWER TYPE QUESTIONS | Q 11. | Page 194

Can a direct current be used for the measurement of electrical conductivity of a solution? If not, why?

SHORT ANSWER TYPE QUESTIONS | Q 12. | Page 194

How does the molar conductivity for the solution of a strong electrolyte vary with concentration? Explain graphically.

SHORT ANSWER TYPE QUESTIONS | Q 13. | Page 194

What is Debye-Huckel-Onsagar equation and what is its significance?

SHORT ANSWER TYPE QUESTIONS | Q 14. | Page 194

Explain why the molar conductivity of a strong electrolytic solution increases only slightly when concentration is decreased.

SHORT ANSWER TYPE QUESTIONS | Q 15. i. | Page 194

What do you understand by molar conductivity at infinite dilution?

SHORT ANSWER TYPE QUESTIONS | Q 15. ii. | Page 194

How does the molar conductivity for the solution of a strong electrolyte vary with concentration? Explain graphically.

SHORT ANSWER TYPE QUESTIONS | Q 16. | Page 194

How does the molar conductivity of a weak electrolytic solution vary with concentration?

SHORT ANSWER TYPE QUESTIONS | Q 17. | Page 194

The molar conductivity at infinite dilution of a strong electrolyte can be obtained by extrapolating the curve Λm vs `sqrt c`, but the same cannot be done for a weak electrolyte. Explain why.

SHORT ANSWER TYPE QUESTIONS | Q 18. | Page 194

Why does the molar conductivity of a weak electrolytic solution increase sharply at very low concentrations?

SHORT ANSWER TYPE QUESTIONS | Q 19. | Page 194

How does the molar conductivity of a weak electrolytic solution vary with concentration?

SHORT ANSWER TYPE QUESTIONS | Q 20. i. | Page 194

What is the effect of dilution on the specific conductivity of a solution?

SHORT ANSWER TYPE QUESTIONS | Q 20. ii. | Page 194

What is the effect of dilution on the equivalent conductivity of a solution?

SHORT ANSWER TYPE QUESTIONS | Q 20. iii. | Page 194

What is the effect of dilution on the molar conductivity of a solution?

SHORT ANSWER TYPE QUESTIONS | Q 21. i. | Page 194

What is a galvanic cell?

SHORT ANSWER TYPE QUESTIONS | Q 21. ii. | Page 194

How can a galvanic cell be constructed?

SHORT ANSWER TYPE QUESTIONS | Q 22. i. | Page 194

What do you understand by a half cell?

SHORT ANSWER TYPE QUESTIONS | Q 22. ii. | Page 194

What are the half cells present in a Daniell cell?

SHORT ANSWER TYPE QUESTIONS | Q 23. i. | Page 194

How would you represent a Daniell cell?

SHORT ANSWER TYPE QUESTIONS | Q 23. ii. | Page 194

How would you represent a Daniell cell?

SHORT ANSWER TYPE QUESTIONS | Q 24. i. | Page 194

Explain why the anode is of negative polarity in a galvanic cell.

SHORT ANSWER TYPE QUESTIONS | Q 24. ii. | Page 194

Explain why the cathode is of positive polarity in a galvanic cell.

SHORT ANSWER TYPE QUESTIONS | Q 25. | Page 194

What type of reactions do occur at the two electrodes at a galvanic cell and what is the nature of the net cell reaction? Explain with an example.

SHORT ANSWER TYPE QUESTIONS | Q 26. i. | Page 194

What is electrode potential?

SHORT ANSWER TYPE QUESTIONS | Q 26. ii. | Page 194

How does electrode potential come into existence?

SHORT ANSWER TYPE QUESTIONS | Q 27. i. | Page 194

What is a salt bridge?

SHORT ANSWER TYPE QUESTIONS | Q 27. ii. | Page 194

What are the functions of a salt bridge in a galvanic cell?

SHORT ANSWER TYPE QUESTIONS | Q 28. | Page 194

Write the ion electron equations for the half cell reactions and overall cell reaction for the cell.

\[\ce{Pt, H2_{(g)} | HCl_{(aq)} || Fe^{3+}, Fe^{2+} | Pt}\]

SHORT ANSWER TYPE QUESTIONS | Q 29. | Page 194

Depict the electrochemical cell in which the cell reaction is

\[\ce{2Cr_{(s)} + 3Cu{^{2+}_{(aq)}} -> 2Cr{^{3+}_{(aq)}} + 3Cu_{(s)}}\]

  1. mark the anode and the cathode;
  2. show movement of electrons and flow of current;
  3. write the half cell reactions.
SHORT ANSWER TYPE QUESTIONS | Q 30. | Page 194

Write the symbolic representation of the electrochemical cell with the cell reaction.

\[\ce{Zn_{(s)} + 2Ag{^+_{(aq)}} -> Zn{^{2+}_{(aq)}} + 2Ag_{(s)}}\]

Indicate the oxidation electrode and the direction of movement of electrons and write the electrode reactions.

SHORT ANSWER TYPE QUESTIONS | Q 31. i. | Page 194

What is standard hydrogen electrode?

SHORT ANSWER TYPE QUESTIONS | Q 31. ii. | Page 194

What is standard hydrogen electrode significance?

SHORT ANSWER TYPE QUESTIONS | Q 32. i. | Page 194

Define electrode potential.

SHORT ANSWER TYPE QUESTIONS | Q 32. ii. | Page 194

It is impossible to measure the potential of a single electrode. Comment.

SHORT ANSWER TYPE QUESTIONS | Q 33. | Page 194

How are standard electrode potentials measured?

SHORT ANSWER TYPE QUESTIONS | Q 34. | Page 194

When a Zn2+/Zn electrode is connected to a SHE, the electrons flow from zinc electrode to hydrogen electrode but the flow of electrons is in opposite direction when a Cu2+/Cu electrode is connected to a SHE. Explain giving reasons.

SHORT ANSWER TYPE QUESTIONS | Q 35. (i) | Page 194

How does the tendency to gain electrons vary when one moves from the top to the bottom in the electrochemical series?

SHORT ANSWER TYPE QUESTIONS | Q 35. (ii) | Page 194

How does the following property vary on moving down the electrochemical series?

Reducing power of the reduced form.

SHORT ANSWER TYPE QUESTIONS | Q 35. (iii) | Page 194

How does the following property vary on moving down the electrochemical series?

Oxidising power of the oxidised form.

SHORT ANSWER TYPE QUESTIONS | Q 36. | Page 194

Justify the statement:

If \[\ce{E^{\circ}_{{M^{n+}/{M}}}}\] is positive, Mn+ can be reduced to M by H2 gas under standard conditions.

SHORT ANSWER TYPE QUESTIONS | Q 37. | Page 194

Comment on the statement:

If \[\ce{E^{\circ}_{{M^{n+}/{M}}}}\] is negative, H+ ions cannot be reduced to H2(g) by the metal M.

SHORT ANSWER TYPE QUESTIONS | Q 38. | Page 194

On what factor does the reactivity of a metal depend and why?

SHORT ANSWER TYPE QUESTIONS | Q 39. | Page 194

Explain, why can zinc displace Cu from an aqueous solution of CuSO4 but Cu cannot displace zinc from aqueous ZnSO4 solution?

SHORT ANSWER TYPE QUESTIONS | Q 40. | Page 194

What is meant by reduction electrode potentials of zinc and copper being −0.76 V and + 0.34 V respectively? Can an aqueous solution of CuSO4 be stored in a zinc vessel? Answer with reason.

SHORT ANSWER TYPE QUESTIONS | Q 41. i. | Page 194

What do you understand by electrochemical series?

SHORT ANSWER TYPE QUESTIONS | Q 41. ii. | Page 194

How does the electrochemical series help in predicting whether a given reaction is feasible in a given direction or not?

SHORT ANSWER TYPE QUESTIONS | Q 42. i. | Page 194

What do you understand by electrochemical series?

SHORT ANSWER TYPE QUESTIONS | Q 42. ii. | Page 194

How does the electrochemical series help in calculating the emf of a standard cell?

SHORT ANSWER TYPE QUESTIONS | Q 43. | Page 194

Give reason why the blue colour of copper sulphate solution is discharged slowly when an iron rod is dipped in it.

Given: \[\ce{E^{\circ}_{{Cu^{2+}/{Cu}}} = 0.34 V}\], \[\ce{E^{\circ}_{{Fe^{2+}/{Fe}}} = -0.44 V}\].

SHORT ANSWER TYPE QUESTIONS | Q 44. | Page 195

Write the equation which correlates the electrode potential of an electrode assembly with the concentration of ions and the temperature. What is the name of the equation and what is its significance?

SHORT ANSWER TYPE QUESTIONS | Q 45. i. | Page 195

What do you understand by EMF of a galvanic cell?

SHORT ANSWER TYPE QUESTIONS | Q 45. ii. | Page 195

How can EMF of a galvanic cell be calculated if the cell is in standard condition?

SHORT ANSWER TYPE QUESTIONS | Q 46. i. | Page 195

Write the Nernst equation for the cell potential of a galvanic cell.

SHORT ANSWER TYPE QUESTIONS | Q 46. ii. | Page 195

Apply the Nernst equation to a Daniell cell.

SHORT ANSWER TYPE QUESTIONS | Q 47. | Page 195

Write the Nernst equation for a cell having the cell reaction. 

\[\ce{aA + bB -> cC + dD}\].

SHORT ANSWER TYPE QUESTIONS | Q 48. i. | Page 195

What is an electrolytic cell?

SHORT ANSWER TYPE QUESTIONS | Q 48. ii. | Page 195

How does electrolytic cell differ from a galvanic cell?

SHORT ANSWER TYPE QUESTIONS | Q 49. i. | Page 195

Define electrolysis.

SHORT ANSWER TYPE QUESTIONS | Q 49. ii. | Page 195

Discuss the electrolysis mechanism by taking the example of fused sodium chloride.

SHORT ANSWER TYPE QUESTIONS | Q 50. i. | Page 195

What is overvoltage?

SHORT ANSWER TYPE QUESTIONS | Q 50. ii. | Page 195

How does overvoltage affect the electrolysis of an aqueous solution of sodium chloride?

SHORT ANSWER TYPE QUESTIONS | Q 51. (i) | Page 195

Predict the products of electrolysis obtained at the electrodes in the case when the electrodes used are of platinum:

An aqueous solution of AgNO3.

SHORT ANSWER TYPE QUESTIONS | Q 51. (ii) | Page 195

Predict the product of electrolysis in the following:

An aqueous solution of AgNO3 with silver electrodes.

SHORT ANSWER TYPE QUESTIONS | Q 52. | Page 195

What are the criteria for product formation during electrolysis?

SHORT ANSWER TYPE QUESTIONS | Q 53. | Page 195

Why does the anode dissolve when an aqueous solution of CuSO4 is subjected to electrolysis using copper electrodes?

SHORT ANSWER TYPE QUESTIONS | Q 54. | Page 195

What are the products of electrolysis of an aqueous solution of dilute sulphuric acid? Explain with reasons.

SHORT ANSWER TYPE QUESTIONS | Q 55. | Page 195

State Faraday’s Laws of electrolysis.

SHORT ANSWER TYPE QUESTIONS | Q 56. | Page 195

How much charge is necessary to liberate one equivalent of a substance and why? Calculate the value of this charge.

SHORT ANSWER TYPE QUESTIONS | Q 57. | Page 195

All the energy released from the reaction \[\ce{X -> Y}\], ΔrG° = −193 KJ mol−1 is used for oxidizing \[\ce{M+ -> M^{3+} + 2e−}\], E° = −0.25 V.

Under standard conditions, the number of moles of M+ oxidized when one mole of X is converted to Y is [F = 96500 C mol−1].

LONG ANSWER TYPE QUESTIONS [Page 196]

Nootan solutions for Chemistry Part 1 and 2 [English] Class 12 ISC 3 Electrochemistry LONG ANSWER TYPE QUESTIONS [Page 196]

LONG ANSWER TYPE QUESTIONS | Q 1. i. | Page 196

What are electrolytic conductors?

LONG ANSWER TYPE QUESTIONS | Q 1. ii. | Page 196

How are electrolytic conductors classified?

LONG ANSWER TYPE QUESTIONS | Q 2. i. | Page 196

Define the following term:

Specific conductance

LONG ANSWER TYPE QUESTIONS | Q 2. ii. | Page 196

Define the term equivalent conductance.

LONG ANSWER TYPE QUESTIONS | Q 2. iii. | Page 196

Define “Molar conductivity”.

LONG ANSWER TYPE QUESTIONS | Q 2. iv. | Page 196

Derive the units of specific conductivities of an electrolytic solution and write expressions which show their mutual relationship.

LONG ANSWER TYPE QUESTIONS | Q 2. v. | Page 196

Derive the units of equivalent conductivity of a solution.

LONG ANSWER TYPE QUESTIONS | Q 2. vi. | Page 196

How is equivalent conductivity related to specific conductivity?

LONG ANSWER TYPE QUESTIONS | Q 2. vii. | Page 196

What is the SI unit of molar conductivity?

LONG ANSWER TYPE QUESTIONS | Q 2. viii. | Page 196

Derive a relationship between molar conductivity and equivalent conductivity.

LONG ANSWER TYPE QUESTIONS | Q 2. ix. | Page 196

What is the relationship between molar conductivity and specific conductivity?

LONG ANSWER TYPE QUESTIONS | Q 3. i. | Page 196

What is cell constant?

LONG ANSWER TYPE QUESTIONS | Q 3. ii. | Page 196

How is cell constant determined?

LONG ANSWER TYPE QUESTIONS | Q 3. iii. | Page 196

What is the significance of the cell constant in the measurement of conductivity of an unknown electrolytic solution?

LONG ANSWER TYPE QUESTIONS | Q 4. i. | Page 196

Discuss the method used to measure the electrolytic conductivity of a solution.

LONG ANSWER TYPE QUESTIONS | Q 4. ii. | Page 196

How would you determine the equivalent and molar conductivities of a given solution?

LONG ANSWER TYPE QUESTIONS | Q 5. (i) | Page 196

How does molar conductance of a strong electrolyte vary with its concentration in solution?

LONG ANSWER TYPE QUESTIONS | Q 5. (ii) | Page 196

How does the molar conductivity of a weak electrolytic solution vary with concentration?

LONG ANSWER TYPE QUESTIONS | Q 6. i. | Page 196

How does the molar conductivity for the solution of a strong electrolyte vary with concentration? Explain graphically.

LONG ANSWER TYPE QUESTIONS | Q 6. ii. | Page 196

What do you understand by molar conductivity at infinite dilution?

LONG ANSWER TYPE QUESTIONS | Q 7. | Page 196

How does the molar conductivity of a weak electrolytic solution vary with concentration?

LONG ANSWER TYPE QUESTIONS | Q 8. i. | Page 196

State and explain Kohlrausch’s law.

LONG ANSWER TYPE QUESTIONS | Q 8. ii. | Page 196

How would you determine the molar conductivity at infinite dilution of NH4OH with the help of Kohlrausch’s law?

LONG ANSWER TYPE QUESTIONS | Q 9. i. | Page 196

What is a galvanic cell?

LONG ANSWER TYPE QUESTIONS | Q 9. ii. | Page 196

Describe the construction and working of a Daniell cell.

LONG ANSWER TYPE QUESTIONS | Q 10. | Page 196

Draw a labelled diagram of Daniell cell and show

  1. electrodes working as anode and cathode and their polarity;
  2. direction of flow of electrons and direction of flow of conventional current;
  3. half cell reactions and the net cell reaction.
LONG ANSWER TYPE QUESTIONS | Q 11. i. | Page 196

What is electrode potential?

LONG ANSWER TYPE QUESTIONS | Q 11. ii. | Page 196

How does electrode potential come into existence?

LONG ANSWER TYPE QUESTIONS | Q 11. iii. | Page 196

Explain with examples the term oxidation potential.

LONG ANSWER TYPE QUESTIONS | Q 11. iv. | Page 196

Explain with examples the term reduction potential.

LONG ANSWER TYPE QUESTIONS | Q 12. i. | Page 196

What do you understand by standard electrode potential?

LONG ANSWER TYPE QUESTIONS | Q 12. ii. | Page 196

How are standard electrode potentials measured?

LONG ANSWER TYPE QUESTIONS | Q 13. i. | Page 196

What do you understand by electrochemical series?

LONG ANSWER TYPE QUESTIONS | Q 13. ii. | Page 196

What are the important features of the electrochemical series?

LONG ANSWER TYPE QUESTIONS | Q 13. iii. (i) | Page 196

How does the electrochemical series help in comparing the relative reducing or oxidising powers of different elements?

LONG ANSWER TYPE QUESTIONS | Q 13. iii. (ii) | Page 196

How does the electrochemical series help in predicting the displacement of hydrogen by metals from dilute acids?

LONG ANSWER TYPE QUESTIONS | Q 14. (i) | Page 196

On the basis of electrochemical series, how would you predict displacement of metals from salt solutions?

LONG ANSWER TYPE QUESTIONS | Q 14. (ii) | Page 196

On the basis of electrochemical series, how would you predict feasibility of a redox reaction?

LONG ANSWER TYPE QUESTIONS | Q 14. (iii) | Page 196

On the basis of electrochemical series, how would you predict thermal stability of oxides of different metals?

LONG ANSWER TYPE QUESTIONS | Q 15. i. | Page 196

What is Nernst equation for the potential of an electrode?

LONG ANSWER TYPE QUESTIONS | Q 15. ii. | Page 196

Write the Nernst equation for a cell having the cell reaction. 

\[\ce{aA + bB -> cC + dD}\].

LONG ANSWER TYPE QUESTIONS | Q 16. i. | Page 196

What do you understand by EMF of a galvanic cell?

LONG ANSWER TYPE QUESTIONS | Q 16. ii. | Page 196

Write the IUPAC convention for calculating the standard emf of a cell.

LONG ANSWER TYPE QUESTIONS | Q 16. iii. | Page 196

Write the Nernst equation for the cell potential of a galvanic cell.

LONG ANSWER TYPE QUESTIONS | Q 17. | Page 196

What is the significance of electrode potentials in predicting the products of electrolysis of an aqueous solution of an electrolyte? Explain with a suitable example.

LONG ANSWER TYPE QUESTIONS | Q 18. | Page 196

Discuss the electrolysis of an aqueous solution of sodium chloride and explain the products formed at the two electrodes.

LONG ANSWER TYPE QUESTIONS | Q 19. | Page 196

Mention the criteria to predict the formation of products during electrolysis of an aqueous solution of an electrolyte. Apply these criteria to the electrolysis of an aqueous solution of copper sulphate using inert electrodes.

LONG ANSWER TYPE QUESTIONS | Q 20. i. | Page 196

State Faraday’s Laws of electrolysis.

LONG ANSWER TYPE QUESTIONS | Q 20. ii. | Page 196

How are Faraday’s laws of electrolysis helpful in exploring the quantitative aspect of electrolysis?

INTEGER TYPE QUESTIONS [Page 196]

Nootan solutions for Chemistry Part 1 and 2 [English] Class 12 ISC 3 Electrochemistry INTEGER TYPE QUESTIONS [Page 196]

INTEGER TYPE QUESTIONS | Q 1. | Page 196

The molar conductivities at infinite dilution of barium chloride, sulphuric acid and hydrochloric acid are 280, 860 and 426 S cm2 mol−1 respectively. The molar conductivity at infinite dilution of barium sulphate is ______ S cm2 mol−1.

(Round off to the nearest integer)

INTEGER TYPE QUESTIONS | Q 2. | Page 196

A KCl solution of conductivity 0.14 S m−1 shows a resistance of 4.19 Ω in a conductivity cell. If the same cell is filled with an HCl solution, the resistance drops to 1.03 Ω. The conductivity of the HCl solution is ______ × 10−2 S m−1

(Round off to the nearest integer)

INTEGER TYPE QUESTIONS | Q 3. | Page 196

At 298 K, the limiting molar conductivity of a weak mono basic acid is 4 × 102 S cm2 mol−1. At 298 K, for an aqueous solution of the acid, the degree of dissociation is ‘α’ and the molar conductivity is y × 102 S cm2 mol−1. At 298 K, upon 20 times dilution with water, the molar conductivity of the solution becomes 3y × 102 S cm2 mol−1.

  1. The value of ‘α’ is ______.
  2. The value of ‘y’ is ______.
INTEGER TYPE QUESTIONS | Q 4. | Page 196

The cell potential for the following cell:

\[\ce{Pt | H2_{(g)} | H{^+_{(aq)}} || Cu^+2 (0.01 M) | Cu}\] is 0.576 at 298 K.

The pH of the solution is ______. (Nearest integer)

INTEGER TYPE QUESTIONS | Q 5. | Page 196

The cell potential for the given cell at 298 K.

\[\ce{Pt | H2_{(g)} (1 bar) | H{^+_{(aq)}} || Cu{^{+2}_{(aq)}} | Cu_{(s)}}\] is 0.31 V.

The pH of the acidic solution is found to be 3 whereas the concentration of Cu+2 is 10−x M. The value of x is ______ (Nearest integer).

(Given, \[\ce{E^{\circ}_{{Cu^{2+}/{Cu}}} = 0.34 V}\] and \[\ce{\frac{2.303 RT}{F} = 0.06 V}\]).

INTEGER TYPE QUESTIONS | Q 6. | Page 196

A solution of Fe2(SO4)3 is electrolysed for ‘x’ min with a current of 1.5 A to deposit 0.3482 g of Fe. The value of ‘x’ is ______. (Nearest integer)

(Given, 1 F = 96500 C mol−1, Atomic mass of Fe = 56)

INTEGER TYPE QUESTIONS | Q 7. | Page 196

\[\ce{Cu_{(s)} + Sn{^{+2}} (0.001 M) -> Cu^{+2} (0.01 M) + Sn_{(s)}}\]

The Gibbs free energy change for the above reaction at 298 K is x × 10−1 KJ mol−1. The value of x is ______ (Nearest integer).

(Given \[\ce{E^{\circ}_{{Cu^{2+}/{Cu}}} = 0.34 V}\], \[\ce{E^{\circ}_{{Sn^{2+}/{Sn}}} = -0.14 V}\], F = 96500 C mol−1)

INTEGER TYPE QUESTIONS | Q 8. | Page 196

For the given reactions

\[\ce{Sn^{+2} + 2e- -> Sn}\]

\[\ce{Sn^{+4} + 2e- -> Sn}\]

The electrode potentials are \[\ce{E^{\circ}_{{Sn^{+2}/{Sn}}}}\] = −0.14 V and \[\ce{E^{\circ}_{{Sn^{+4}/{Sn}}}}\] = 0.010 V. The magnitude of standard electrode potential for \[\ce{Sn^{+4}/Sn^{+2}}\] i.e., \[\ce{E^{\circ}_{{Sn^{+4}/{Sn^{+2}}}}}\] is ______ × 10−2 V (Nearest integer).

INTEGER TYPE QUESTIONS | Q 9. | Page 196

The reduction potential (E° in V) of \[\ce{MnO^-_{4(aq)}/Mn_{(s)}}\] is ______.

Given \[\ce{E^{\circ}_{MnO^-_{4(aq)}/MnO_{2(s)}}}\] = 1.68 V

\[\ce{E^{\circ}_{MnO_{2(s)}/Mn^{+2}_{(aq)}}}\] = 1.21 V

\[\ce{E^{\circ}_{Mn^{+2}_{(aq)}/Mn_{(s)}}}\] = −1.03 V

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS [Pages 197 - 203]

Nootan solutions for Chemistry Part 1 and 2 [English] Class 12 ISC 3 Electrochemistry OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS [Pages 197 - 203]

Choose the correct option in the following questions.

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 1. | Page 197

Molten sodium chloride conducts electricity due to the presence of ______.

  • free electrons

  • free ions

  • free molecules

  • free atoms of Na and Cl

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 2. | Page 197

When one Faraday of electric current is passed, the mass deposited is equal to ______.

  • one gram equivalent

  • one gram mole

  • half of electrochemical equivalent

  • half gram equivalent

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 3. | Page 197

A current liberated 0.50 g of hydrogen in 2 hours. How many grams of copper can be liberated by the same current flowing for the same time in CuSO4 solution?

  • 12.7 g

  • 15.9 g

  • 31.8 g

  • 63.5 g

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 4. | Page 197

One Faraday of charge was passed through the electrolytic cells placed in series containing solutions of Ag+, Ni2+ and Cr3+ respectively. The amounts of Ag (At. mass = 108), Ni (At. mass = 59) and Cr (At. mass = 52) deposited will be:

  • Ag Ni Cr
    108 g 29.5 g 17.5 g
  • Ag Ni Cr
    108 g 59.0 g 52.0 g
  • Ag Ni Cr
    108 g 108.0 g 108.0 g
  • Ag Ni Cr
    108 g 117.5 g 166.0 g
OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 5. | Page 197

Which one is the correct equation that represents the first law of electrolysis?

  • mZ = ct

    Where, c represents the magnitude of current in amperes.

  • m = cZt

    Where, c represents the magnitude of current in amperes.

  • mc = Zt

    Where, c represents the magnitude of current in amperes.

  • c = mZt

    Where, c represents the magnitude of current in amperes.

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 6. | Page 197

When electricity is passed through a solution of AlCl3, 13.5 g of Al is discharged, the amount of charge passed is ______.

  • 1.5 F

  • 0.5 F

  • 1.0 F

  • 2.0 F

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 7. | Page 197

The cathodic reaction in the electrolysis of dilute H2SO4 with platinum electrodes is ______.

  • oxidation

  • reduction

  • both oxidation and reduction

  • neutralisation

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 8. | Page 198

The reaction, \[\ce{\frac{1}{2} H2_{(g)} + AgCl_{(s)} -> H^+_{ (aq)} + Cl^-_{ (aq)} + Ag_{(s)}}\], occurs in the galvanic cell

  • \[\ce{Ag | AgCl_{(s)} | KCl (soln) || AgNO3 (soln) | Ag}\]

  • \[\ce{Pt | H2_{(g)} | HCl (soln) || AgNO3 (soln) | Ag}\]

  • \[\ce{Pt | H2_{(g)} | HCl (soln) || AgCl_{(s)} | Ag}\]

  • \[\ce{Pt | H2_{(g)} | KCl (soln) || AgCl_{(s)} | Ag}\]

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 9. | Page 198

The standard oxidation potentials, \[\ce{E{^{\circ}_{oxi}}}\] for the half cell reactions are as follows:

\[\ce{Zn -> Zn^2+ + 2e-}\]; \[\ce{E{^{\circ}_{oxi}}}\] = +0.76 V

\[\ce{Fe -> Fe^2+ + 2e-}\]; \[\ce{E{^{\circ}_{oxi}}}\] = +0.41 V

The emf of the cell, \[\ce{Fe^2+ + Zn -> Zn^2 + Fe}\], is ______.

  • +0.35 V

  • −0.35 V

  • +1.17 V

  • −1.17 V

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 10. | Page 198

If a spoon of copper metal is placed in a solution of ferrous sulphate, ______.

  • Cu will precipitate out

  • iron will precipitate

  • Cu and Fe will precipitate

  • no reaction will take place

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 11. | Page 198

Which one will liberate Br2 from KBr?

  • H2

  • I2

  • Cl2

  • SO2

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 12. | Page 198

The standard reduction potentials at 25°C for the following half cell reactions are given against each:

\[\ce{Zn{^{2+}_{(aq)}} + 2e- -> Zn_{(s)}}\] = −0.762 V

\[\ce{Cr{^{3+}_{(aq)}} + 3e- -> Cr_{(s)}}\] = −0.740 V

\[\ce{2H+ + 2e- -> H2_{(g)}}\] = 0.000 V

\[\ce{Fe^3+ + e- -> Fe^2+}\] = 0.770 V

Which is the strongest reducing agent?

  • Zn

  • Cr

  • H2(g)

  • \[\ce{Fe{^{2+}_{(aq)}}}\]

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 13. | Page 198

Which is not true for a standard hydrogen electrode?

  • The pressure of hydrogen is 1 atm.

  • The hydrogen ion concentration is 1 M.

  • Temperature is 25°C.

  • H2 gas is not absorbed by platinum electrode.

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 14. | Page 198

The standard electrode potentials of four elements A, B, C, D are −3.05, 1.66, −0.40 and 0.80 volts respectively. The highest chemical activity will be shown by ______.

  • A

  • B

  • C

  • D

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 15. | Page 198

Which one of the following will increase the voltage of the cell whose cell reaction is given below?

\[\ce{Sn + 2Ag+ -> Sn^2+ + 2Ag}\]

  • Increase in the size of silver rod.

  • Increase in the concentration of Sn2+ ions.

  • Increase in the concentration of Ag+ ions.

  • None of the above.

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 16. | Page 198

When electric current is passed through a cell having an electrolyte, the positive ions move towards the cathode and the negative ions towards the anode. If the cathode is pulled out of the solution ______.

  • the positive and the negative ions will move towards the anode

  • the positive ions will start moving towards the anode

  • the negative ions will continue to move towards the anode; the positive ions will stop moving

  • the positive ions and the negative ions will start moving randomly

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 17. | Page 198

If a salt bridge is removed from the two half cells, the voltage ______.

  • drops to zero

  • does not change

  • increases gradually

  • increases rapidly

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 18. | Page 198

1 Faraday of electricity will liberate 1 g atom of the metal from ______.

  • fused NaCl

  • aqueous BaCl2

  • aqueous CuSO4

  • aqueous AlCl3

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 19. | Page 198

The metal that cannot be obtained by electrolysis of the aqueous solution of its salts is ______.

  • Ag

  • Cr

  • Cu

  • Al

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 20. | Page 198

The standard reduction electrode potential values of the elements A, B and C are +0.68, −2.50 and −0.50 V respectively. The order of their reducing power is ______.

  • A > B > C

  • A > C > B

  • C > B > A

  • B > C > A

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 21. | Page 198

How many electrons carry one coulomb of charge?

  • 6.02 × 1021

  • 6.24 × 1018

  • 6.24 × 1015

  • 6.02 × 1016

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 22. | Page 198

If \[\ce{E^{\circ}_{{Ag^{+}/{Ag}}}}\] = +0.80 V and \[\ce{E^{\circ}_{{Sn^{2+}/{Sn}}}}\] = −0.14 V, the standard emf of the cell \[\ce{Sn | Sn^2+ ||  Ag+ | Ag}\], will be ______.

  • 0.66 V

  • 0.80 V

  • 0.94 V

  • 1.80 V

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 23. | Page 198

The hydrogen electrode is dipped in a solution of pH = 3 at 25°C. The reduction potential of the electrode would be ______.

  • 0.177 V

  • −0.177 V

  • 0.087 V

  • 0.059 V

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 24. | Page 198

The standard EMF for the cell reaction,
\[\ce{Zn + Cu^{2+} -> Zn^{2+} + Cu}\], 
is 1.10 V at 25°C. The EMF of the cell reaction, when 0.1 M Cu2+ and 0.1 M Zn2+ solutions are used at 25°C is:

  • 1.10 V

  • 0.110 V

  • −1.10 V

  • −0.110 V

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 25. | Page 198

The number of Faradays required to reduce one mol of Cu2+ to metallic copper is ______.

  • one

  • two

  • three

  • four

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 26. | Page 199

A standard hydrogen electrode has zero electrode potential because ______.

  • hydrogen is easiest to oxidise.

  • the electrode potential is assumed to be zero.

  • hydrogen has only one electron.

  • hydrogen is the lightest element.

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 27. | Page 199

The standard reduction potential values of three metallic cations, X, Y, Z are 0.52, −3.03 and −1.18 V respectively. The order of reducing power of the corresponding metals is ______.

  • Y > Z > X

  • X > Y > Z

  • Z > Y > X

  • Z > X > Y

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 28. | Page 199

A gas X at 1 atm is bubbled through a solution containing a mixture of 1 MY and 1 MZ at 25°C. If the reduction potential of Z > Y > X, then ______.

  • Y will oxidise X and not Z

  • Y will oxidise Z and not X

  • Y will oxidise both X and Z

  • Y will reduce both X and Z

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 29. | Page 199

For the electrochemical cell:

\[\ce{M | M+ || X- | X}\]; 

\[\ce{E^{\circ}_{{M^{+}/{M}}}}\] = 0.44 V,

\[\ce{E^{\circ}_{X/X^-}}\] = 0.33 V

Which of the following is TRUE for this data?

  • \[\ce{E^{\circ}_{cell}}\] = −0.77V

  • \[\ce{E^{\circ}_{cell}}\] = 0.77V

  • \[\ce{M+ + X- -> M + X}\] is a spontaneous reaction.

  • \[\ce{M + X -> M+ + X-}\] is a spontaneous reaction.

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 30. | Page 199

At 25°C, the standard e.m.f. of a cell having reaction involving two electron change is found to be 0.295 V. The equilibrium constant of the reaction is ______.

  • 29.5 × 10−2

  • 10

  • 1 × 1010

  • 29.5 × 1010

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 31. | Page 199

Saturated solution of KNO3 is used to make salt bridge because:

  • velocity of K+ is greater than that of \[\ce{NO^-_3}\].

  • velocity of \[\ce{NO^-_3}\] is greater than that of K+.

  • velocities of both K+ and \[\ce{NO^-_3}\] are nearly the same.

  • KNO3 is highly soluble in water.

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 32. | Page 199

The correct order of equivalent conductance at infinite dilution of LiCl, NaCl and KCl is ______.

  • LiCl > NaCl > KCl

  • KCl > NaCl > LiCl

  • NaCl > KCl > LiCl

  • LiCl > KCl > NaCl

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 33. | Page 199

For a cell given below:

\[\ce{Ag | Ag+ || Cu^2+ | Cu}\]

\[\ce{Ag+ + e- -> Ag}\]; E° = x

\[\ce{Cu^2+ + 2e- -> Cu}\]; E° = y

\[\ce{E{^{\circ}_{cell}}}\] is ______.

  • x + 2y

  • 2x + y

  • y − x

  • y − 2x

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 34. | Page 199

Conductivity (siemens, S) is directly proportional to area of the vessel and the concentration of the solution in it and is inversely proportional to the length of the vessel, then constant of proportionality is expressed in ______.

  • S m mol−1

  • S2 m2 mol−2

  • S m2 mol−1

  • S2 m2 mol

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 35. | Page 199

When during electrolysis of a solution of AgNO3, 9650 coulombs of charge pass through the electroplating bath, the mass of silver deposited on the cathode will be ______.

  • 10.8 g

  • 21.6 g

  • 108 g

  • 1.08 g

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 36. | Page 199

For the redox reaction, 

\[\ce{Zn_{(s)} + Cu^2+ (0.1 M) -> Zn^2+ (1M) + Cu_{(s)}}\],

taking place in a cell, \[\ce{E{^{\circ}_{cell}}}\] is 1.10 volt. Ecell for the cell will be: \[\ce{(2.303 \frac{RT}{F} = 0.0591)}\]

  • 2.14 V

  • 1.80 V

  • 1.07 V

  • 0.82 V

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 37. | Page 199

For a cell reaction in involving a two electron change, the Stanford emf of the cell is found to be 0.295 V at 25°C. The equilibrium constant of the reaction at 25°C will be:

  • 1 × 10−10

  • 29.5 × 10−2

  • 10

  • 1 × 1010

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 38. | Page 199

Standard reduction electrode potentials of three metals A, B and C are +0.5 V, −3.0 V and −1.2 V respectively. The reducing power of these metals is ______.

  • B > C > A

  • A > B > C

  • C > B > A

  • A > C > B

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 39. | Page 199

In a hydrogen-oxygen fuel cell, combustion of hydrogen occurs to ______.

  • Produce high purity water

  • Created defection difference between two electrodes

  • Generated heat

  • Remove absorbed oxygen form electron surface

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 40. | Page 199

Consider the following E° values:

\[\ce{E^{\circ}_{{Fe^{3+}/{Fe^{2+}}}}}\] = + 0.77 V

\[\ce{E^{\circ}_{{Sn^{2+}/{Sn}}}}\] = −0.14 V.

Under standard conditions the potential for the reaction:

\[\ce{Sn_{(s)} +  2Fe^{3+}_{ (aq)} -> 2Fe^{2+}_{ (aq)} + Sn^{2+}_{ (aq)}}\] is:

  • 1.68 V

  • 1.40 V

  • 0.91 V

  • 0.63 V

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 41. | Page 199

The standard emf of a cell, involving one electron charge is found to be 0.591 V at 25°C. The equilibrium constant of the reaction is ______. (F = 96,500 C mol−1)

  • 1.0 × 101

  • 1.0 × 105

  • 1.0 × 1010

  • 1.0 × 1030

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 42. | Page 199

The limiting molar conductivities Λ° for NaCl, KBr and KCl are 126, 152 and 150 S cm2 mol–1 respectively. The limiting molar conductivity Λ° for NaBr is ______.

  • 278 S cm2 mol–1 

  • 176 S cm2 mol–1 

  • 128 S cm2 mol–1 

  • 302 S cm2 mol–1 

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 43. | Page 199

In a cell that utilises the reaction \[\ce{Zn_{(s)} + 2H{^{+}_{(aq)}} -> Zn{^{2+}_{(aq)}} + H2_{(g)}}\] addition of H2SO4 to cathode compartment will ______.

  • lower the E and shift equilibrium to the left.

  • lower the E and shift the equilibrium to the right.

  • increase the E and shift the equilibrium to the right.

  • increase the E and shift the equilibrium to the left.

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 44. | Page 200

The \[\ce{E^{\circ}_{M^{3+}/M^{2+}}}\] values for Cr, Mn, Fe and Co are −0.41, +1.57, +0.77 and +1.97 V respectively. For which one of these metals the change in oxidation state from +2 to +3 is easiest?

  • Cr

  • Mn

  • Fe

  • Co

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 45. | Page 200

Aluminium oxide may be electrolysed at 1000°C to furnish aluminium metal.

(Atomic mass = 27 amu; 1 Faraday = 96,500 coulombs)

The cathode reaction is:

\[\ce{Al^3+ + 3e- -> Al^0}\]

To prepare 5.12 kg of aluminium metal by this method would require:

  • 5.49 × 101 C of electricity

  • 5.49 × 104 C of electricity

  • 1.83 × 107 C of electricity

  • 5.49 × 107 C of electricity

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 46. | Page 200

Given the data at 25°C,

\[\ce{Ag + I- -> AgI + e-}\]; E° = – 0.152 V

\[\ce{Ag -> Ag+ + e-}\]; E° = – 0.800 V.

What is the value of Ksp for AgI?

\[\ce{\left(2.303 \frac{RT}{F} = 0.059 V\right)}\]

  • −8.12

  • +8.612

  • −37.83

  • −16.13

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 47. | Page 200

Resistance of a conductivity cell filled with a solution of an electrolyte of concentration 0.1 M is 100 Ω. The conductivity of this solution is 1.29 S m−1. Resistance of the same cell when filled with 0.02 M of the same solution is 520 Ω. The molar conductivity of 0.02 M solution of the electrolyte will be ______.

  • 124 × 10−4 S m2 mol−1

  • 1240 × 10−4 S m2 mol−1

  • 1.24 × 10−4 S m2 mol−1

  • 12.4 × 10−4 S m2 mol−1

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 48. | Page 200

The cell, \[\ce{Zn | Zn^{2+} (1 M) || Cu^{2+} (1 M) | Cu}\], (\[\ce{E^{\circ}_{cell} = 1.10 V}\]), was allowed to be completely discharged at 298 K. The relative concentration of Zn2+ to \[\ce{Cu^{2+}\left(\frac{[Zn^{2+}]}{[Cu{2+}]}\right)}\] is:

  • antilog (24.08)

  • 37.3

  • 1037.3

  • 9.65 × 104

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 49. | Page 200

The equivalent conductances of two strong electrolytes at infinite dilution in H2O (where ions move freely through a solution) at 25°C are given below:

\[\ce{\Lambda^{\circ}_{CH_3COONa}}\] = 91.0 S cm2/equiv.

\[\ce{\Lambda^{\circ}_{HCl}}\] = 426.2 S cm2/equiv.

What additional information/quantity does one need to calculate Λ° of an aqueous solution of acetic acid?

  • Λ° of NaCl

  • Λ° of CH3COOK

  • The limiting equivalent conductance of H+.

  • Λ° of chloroacetic acid (ClCH2COOH)

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 50. | Page 200

Given \[\ce{E^{\circ}_{Cr^{3+}/Cr}}\] = −0.72 V, \[\ce{E^{\circ}_{Fe^{2+}/Fe}}\] = −0.42 V. The potential for the cell \[\ce{Cr | Cr^{3+} (0.1 M) || Fe^{2+} (0.01 M) | Fe}\] is:

  • 0.26 V

  • 0.339 V

  • −0.339 V

  • −0.26 V

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 51. | Page 200

For the reduction of silver ions with copper metal, the standard cell potential was found to be +0.46 V at 25°C. The value of standard Gibbs energy, ΔG° will be ______. (F = 96500 C mol−1)

  • −89.0 kJ

  • −89.0 J

  • −44.5 kJ

  • −98.0 kJ

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 52. | Page 200

Standard electrode potential of three metals X, Y and Z are –1.2 V, +0.5 V and –3.0 V, respectively. The reducing power of these metals will be ______.

  • Y > Z > X

  • X > Y > Z

  • Z > X > Y

  • Z > X > Y

  • Y > X > Z

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 53. | Page 200

If the \[\ce{E^{\circ}_{cell}}\] for a given reaction has a negative value, then which of the following gives the correct relationships for the values of ΔG° and Keq?

  • ΔG° < 0; Keq > 1

  • ΔG° < 0; Keq < 1

  • ΔG° > 0; Keq < 1

  • ΔG° > 0; Keq > 1

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 54. | Page 200

The electrode potentials for \[\ce{Cu{^{2+}_{(aq)}} + e- -> Cu{^+_{(aq)}}}\] and \[\ce{Cu{^{+}_{(aq)}} + e- -> Cu_{(s)}}\] are +0.15 V and +0.50 V respectively. The value of  \[\ce{E^{\circ}_{{Cu^{2+}/{Cu}}}}\] will be:

  • 0.325 V

  • 0.650 V

  • 0.150 V

  • 0.500 V

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 55. | Page 200

A buffer solution is prepared in which the concentration of NH3 is 0.30 M and the concentration of \[\ce{NH^+_4}\] is 0.20 M. If the equilibrium constant, Kb for NH3 equals 1.8 × 10−5, what is the pH of this solution? (log 2.7 = 0.43)

  • 9.43

  • 11.72

  • 8.73

  • 9.08

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 56. | Page 200

Standard electrode potential for Sn4+/Sn2+ couple is +0.15 V and that for the Cr3+/Cr couple is −0.74. These two couples in their standard state are connected to make a cell. The cell potential will be ______.

  • +0.89 V

  • +0.18 V

  • +1.83 V

  • +1.199 V

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 57. | Page 201

\[\ce{\Lambda^{\circ}_m(NH_4OH)}\] [i.e., \[\ce{\Lambda^{\circ}_m(NH4OH)}\]] is equal to ______.

  • \[\ce{\Lambda^{\circ}_m(NH4Cl) + \Lambda^{\circ}_m(NaCl) - \Lambda^{\circ}_m(NaOH)}\]

  • \[\ce{\Lambda^{\circ}_m(NaOH) + \Lambda^{\circ}_m(NaCl) - \Lambda^{\circ}_m(NH4Cl)}\]

  • \[\ce{\Lambda^{\circ}_m(NH4OH) + \Lambda^{\circ}_m(NH4Cl) - \Lambda^{\circ}_m(HCl)}\]

  • \[\ce{\Lambda^{\circ}_m(NH4Cl) + \Lambda^{\circ}_m(NaOH) - \Lambda^{\circ}_m(NaCl)}\]

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 58. | Page 201

When 0.1 mol \[\ce{MnO^{2-}_4}\] is oxidised, the quantity of electricity required to completely oxidise \[\ce{MnO^{2-}_4}\] to \[\ce{MnO^-_4}\] is ______.

  • 96500 C

  • 2 × 96500 C

  • 9650 C

  • 96.50 C

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 59. | Page 201

The weight of silver (at. wt. = 108) displaced by a quantity of electricity which displaces 5600 mL of O2 at STP will be ______.

  • 5.4 g

  • 10.8 g

  • 54.0 g

  • 108.0 g

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 60. | Page 201

Resistance of 0.2 M solution of an electrolyte is 50 Ω. The specific conductance of the solution is 1.4 S m−1. The resistance of 0.5 M solution of the same electrolyte is 280 Ω. The molar conductivity of 0.5 M solution of the electrolyte in S mol−1 is ______.

  • 5 × 10−4

  • 5 × 10−3

  • 5 × 103

  • 5 × 102

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 61. | Page 201

The equivalent conductance of NaCl at concentration C and at infinite dilution are λc and λ, respectively. The correct relationship between λc and λ is given as:

  • λc = λ+ (B)C

  • λc = λ− (B)C

  • λc = `lambda_infty - (B) sqrt C`

  • λc = `lambda_infty + (B) sqrt C`

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 62. | Page 201

The metal that cannot be obtained by the electrolysis of an aqueous solution of its salts is ______.

  • Ag

  • Ca

  • Cu

  • Cr

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 63. | Page 201

Given below are the half-cell reactions:

\[\ce{Mn^2+ + 2e- -> Mn}\], E° = −1.18 V

\[\ce{2(Mn^3+ + e- -> Mn^2+)}\], E° = +1.51 V

The E° for \[\ce{3Mn^2+ -> Mn + 2Mn^3+}\] will be ______.

  • −2.69 V, the reaction will not occur.

  • −2.69 V, the reaction will occur.

  • −0.33 V, the reaction will not occur.

  • −0.33 V, the reaction will occur.

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 64. | Page 201

The electrochemical equivalent is the amount of substance which gets deposited from its solution on passing electrical charge equal to ______.

  • 96,500 coulombs

  • 1 coulomb

  • 60 coulombs

  • 965 coulombs

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 65. | Page 201

Two Faraday of electricity is passed through a solution of CuSO4. The mass of copper deposited at the cathode is ______. (at. mass of Cu = 63.5 amu)

  • 0 g

  • 63.5 g

  • 2 g

  • 127 g

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 66. | Page 201

Galvanization is applying a coating of ______.

  • Cu

  • Zn

  • Pb

  • Cr

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 67. | Page 201

The pressure of H2 required to make the potential of H2-electrode zero in pure water at 298 K is ______.

  • 10−14 atm

  • 10−12 atm

  • 10−10 atm

  • 10−4 atm

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 68. | Page 201

In the electrochemical cell, Zn | ZnSO4 (0.01 M) || CuSO4 (1.0 M) | Cu, the emf of this Daniell cell is E1. When the concentration of ZnSO4 is changed to 1.0 M and that of CuSO4 changed to 0.01 M, the emf changes to E2. From the following, which one is the relationship between E1 and E2?

`("Given", (RT)/F = 0.059)`

  • E1 = E2

  • E1 < E2

  • E1 > E2

  • E2 = 0 ≠ E1

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 69. | Page 201

Given: \[\ce{E^{\circ}_{Cl_2/Cl^-}}\] = 1.36 V, \[\ce{E^{\circ}_{Cr^{3+}/Cr}}\] = −0.74 V

\[\ce{E^{\circ}_{Cr_2O^{2-}_7/Cr^{3+}}}\] = 1.33 V, \[\ce{E^{\circ}_{MnO^-_4/Mn^{2+}}}\] = 1.51 V

Among the following, the strongest reducing agent is:

  • Cr3+

  • Cl

  • Cr

  • Mn2+

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 70. | Page 201

How long (approximate) should water be electrolysed by passing through 100 amperes current so that the oxygen is released can completely burn 27.66 g of diborane? 

(Atomic weight of B = 10.8 u)

  • 6.4 hours

  • 0.8 hours

  • 3.2 hours

  • 1.6 hours

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 71. | Page 201

Consider the change in the oxidation state of Bromine corresponding to different emf values as shown in the expression below:

\[\ce{BrO^-_4 ->[1.82 V] BrO^-_3 ->[1.5 V] HBrO ->[1.595 V] Br2 ->[1.0652 V] Br^-}\]

Then the species undergoing disproportionation is:

  • Br2

  • \[\ce{BrO^-_4}\]

  • \[\ce{BrO^-_3}\]

  • HBrO

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 72. | Page 201

Consider the statements S1 and S2.

S1: Conductivity always increases with decrease in the concentration of electrolyte.

S2: Molar conductivity always increases with decrease in the concentration of electrolyte.

The correct option among the following is:

  • Both S1 and S2 are wrong.

  • S1 is correct and S2 is wrong.

  • Both S1 and S2 are correct.

  • S1 is wrong and S2 is correct.

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 73. | Page 202

Which one of the following graphs between molar conductivity (Λm) versus `sqrt C` is correct?

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 74. | Page 202

Following limiting molar conductivities are given as:

\[\ce{\lambda^{\circ}_{m} (H2SO4)}\] = x S cm2 mol−1

\[\ce{\lambda{^{\circ}_{m}} (K2SO4)}\] = y S cm2 mol−1

\[\ce{\lambda{^{\circ}_{m}} (CH3COOK)}\] = z S cm2 mol−1

\[\ce{\lambda^{\circ}_{m}}\] (in S cm2 mol−1) for CH3COOH will be:

  • \[\ce{\frac{(x - y)}{2} + z}\]

  • x − y + 2z

  • x + y + z

  • x − y + z

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 75. | Page 202

The standard electrode potential (E°) values of Al3+/Al, Ag+/Ag, K+/K and Cr3+/Cr are −1.66 V, 0.80 V, −2.93 V and −0.74 V, respectively. The correct decreasing order of reducing power of the metal is ______.

  • Al > K > Ag > Cr

  • Ag > Cr > Al > K

  • K > Al > Cr > Ag

  • K > Al > Ag > Cr

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 76. | Page 202

For the cell reaction:

\[\ce{2Fe^{3+}_{ (aq)} + 2l^-_{ (aq)} -> 2Fe^{2+}_{ (aq)} + l2_{(aq)}}\]

\[\ce{E{^{\circ}_{cell}}}\] = 0.24 V at 298 K. The standard Gibbs energy (ΔrG°) of the cell reaction is:

[Given that Faraday constant, F = 96500 C mol−1]

  • −23.16 kJ mol−1

  • 46.32 kJ mol−1

  • 23.16 kJ mol−1

  • −46.32 kJ mol−1

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 77. | Page 202

For a cell involving one electron \[\ce{E^{\circ}_{cell}}\] = 0.59 V at 298 K, the equilibrium constant for the cell reaction is:

[Given that \[\ce{\frac{2.303 RT}{F}}\] = 0.059 V at T = 298 K]

  • 1.0 × 102

  • 1.0 × 105

  • 1.0 × 1010

  • 1.0 × 1030

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 78. | Page 202

On electrolysis of dilute sulphuric acid using platinum electrodes, the product obtained at the anode will be ______.

  • Hydrogen gas

  • Oxygen gas

  • Hydrogen sulphide (H2S) gas

  • Sulphur dioxide (SO2) gas

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 79. | Page 202

The number of Faradays (F) required to produce 20 g of calcium from molten CaCl2 (Atomic mass of Ca = 40 g mol−1) is ______.

  • 1

  • 2

  • 3

  • 4

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 80. | Page 202

Let CNaCl and \[\ce{C{_{BaSO_4}}}\] be the conductances (in S) measured for saturated aqueous solutions of NaCl and BaSO4 respectively, at a temperature T. Which of the following is false?

  • Ionic mobilities of ions from both salts increase with T.

  • CNaCl >> \[\ce{C{_{BaSO_4}}}\], at a given T

  • \[\ce{C{_{BaSO_4}}}\] (T2) > \[\ce{C{_{BaSO_4}}}\] (T1) for T2 > T1

  • CNaCl (T2) > CNaCl (T1) for T2 > T1

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 81. | Page 202

250 mL of a waste solution obtained from the workshop of a goldsmith contains 0.1 M AgNO3 and 0.1 M AuCl. The solution was electrolyzed at 2 V by passing a current of 1 A for 15 minutes. The metal/metals electrodeposited will be ______.

(\[\ce{E^{\circ}_{Ag^+/Ag}}\] = 0.80 V, \[\ce{E^{\circ}_{Au^{2+}/Au}}\] = 1.69 V)

  • silver and gold in proportion to their atomic weights

  • silver and gold in equal mass proportion

  • only silver

  • only gold

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 82. | Page 202

The molar conductance of NaCl, HCl and CH3COONa at infinite dilution are 126.45, 426.16 and 91.0 S cm2 mol−1 respectively. The molar conductance of CH3COOH at infinite dilution is ______.

Choose the right option for your answer.

  • 540.48 S cm2 mol−1

  • 201.28 S cm2 mol−1

  • 390.71 S cm2 mol−1

  • 698.28 S cm2 mol−1

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 83. | Page 202

The pKb of dimethylamine and pKa of acetic acid are 3.27 and 4.77 respectively at T(K). The correct option for the pH of dimethylammonium acetate solution is ______.

  • 6.25

  • 8.50

  • 5.50

  • 7.75

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 84. | Page 202

The molar conductivity of 0.007 M acetic acid is 20 S cm2 mol−1. What is the dissociation constant of acetic acid? Choose the correct option.

\[\begin{array}{cc}
\end{array}\]\[\begin{bmatrix}
\ce{\Lambda^{\circ}_{H^+} = 350 S cm^2 mol^{-1}}\\
\ce{\Lambda^{\circ}_{CH_3COO^-} = 50 S cm^2 mol^{-1}}
\end{bmatrix}\]

  • 2.50 × 10−5 mol L−1

  • 1.75 × 10−4 mol L−1

  • 2.50 × 10−4 mol L−1

  • 1.75 × 10−5 mol L−1

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 85. | Page 202

Some standard electrode potentials at 298 K are given below:

Pb+2/Pb −0.13 V
Ni+2/Ni −0.24 V
Cd+2/Cd −0.40 V
Fe+2/Fe −0.44 V

To a solution containing 0.001 M of X+2 and 0.1 M of Y+2, the metal rods X and Y are inserted (at 298 K) and connected by a conducting wire. This resulted in dissolution of X. The correct combination(s) of X and Y respectively is (are):

(Given R = 8.314 J K−1 mol−1, F = 96500 (mol−1)

  • Cd and Ni

  • Cd and Fe

  • Ni and Pb

  • Ni and Fe

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 86. | Page 203

At 298 K, the standard electrode potentials of Cu+2/Cu, Zn+2/Zn, Fe+2/Fe and Ag+/Ag are 0.34 V, −0.76 V, −0.44 V and −0.80 V respectively.

On the basis of standard electrode potential, predict which of the following reaction cannot occur?

  • \[\ce{CuSO4_{(aq)} + Fe_{(s)} -> FeSO4_{(aq)} + Cu_{(s)}}\]

  • \[\ce{FeSO4_{(aq)} + Zn_{(s)} -> ZnSO4_{(aq)} + Fe_{(s)}}\]

  • \[\ce{2CuSO4_{(aq)} + 2Ag_{(s)} -> 2Cu_{(s)} + Ag2SO4_{(aq)}}\]

  • \[\ce{CuSO4_{(aq)} + Zn_{(s)} -> ZnSO4_{(aq)} + Cu_{(s)}}\]

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 87. | Page 203

Given below are half cell reactions:

\[\ce{MnO^-_4 + 8H+ + 5e- -> Mn^{+2} + 4H2O}\]

\[\ce{E^{\circ}_{Mn^{+2}/MnO^-_4}}\] = −1.510 V

\[\ce{\frac{1}{2} O2 + 2H+ + 2e- -> H2O}\]

\[\ce{E^{\circ}_{O_2/H_2O}}\] = +1.223 V

Will the permanganate ion \[\ce{MnO^-_4}\] liberate O2 from water in presence of an acid?

  • No, because \[\ce{E^{\circ}_{cell}}\] = −0.287 V

  • Yes, because \[\ce{E^{\circ}_{cell}}\] = +2.733 V

  • No, because \[\ce{E^{\circ}_{cell}}\] = −2.733 V

  • Yes, because \[\ce{E^{\circ}_{cell}}\] = +0.287 V

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 88. | Page 203

Find the emf of the cell in which the following reaction takes place at 298 K.

\[\ce{Ni_{(s)} + 2Ag+ (0.001 M) -> Ni^{+2} (0.001 M) + 2Ag_{(s)}}\]

(Given that \[\ce{E{^{\circ}_{cell}}}\] = 1.05 V, \[\ce{\frac{2.303 RT}{F}}\] = 0.059 at 298 K)

  • 1.385 V

  • 0.9615 V

  • 1.05 V

  • 1.0385 V

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 89. | Page 203

The `((del E)/(del T))_P`of different types of half cells are as follows:

A B C D
1 × 10−4 2 × 10−4 0.1 × 10−4 0.2 × 10−4

(where E is the electromotive force)

Which of the above half cells would be preferred to be used as reference electrode?

  • A

  • B

  • C

  • D

OBJECTIVE (MULTIPLE CHOICE) TYPE QUESTIONS | Q 90. | Page 203

The correct order of reduction potentials of the following pairs is:

  1. Cl2/Cl
  2. I2/I
  3. Ag+/Ag
  4. Na+/Na
  5. Li+/Li

Choose the correct answer from the options given below:

  • A > C > B > D > E

  • A > B > C > D > E

  • A > C > B > E > D

  • A > B > C > E > D

FILL IN THE BLANKS TYPE QUESTIONS [Pages 205 - 206]

Nootan solutions for Chemistry Part 1 and 2 [English] Class 12 ISC 3 Electrochemistry FILL IN THE BLANKS TYPE QUESTIONS [Pages 205 - 206]

FILL IN THE BLANKS TYPE QUESTIONS | Q 1. | Page 205

The conduction of current by a conductor is either due to flow of ______ or due to the movement of ______.

FILL IN THE BLANKS TYPE QUESTIONS | Q 2. | Page 205

The electrolytic conduction ______ with a rise in temperature.

FILL IN THE BLANKS TYPE QUESTIONS | Q 3. | Page 205

The fraction of total number of moles which undergoes dissociation is called ______.

FILL IN THE BLANKS TYPE QUESTIONS | Q 4. | Page 205

The ions remain ______ in solution.

FILL IN THE BLANKS TYPE QUESTIONS | Q 5. | Page 205

Higher the interaction between solute and solvent particles ______ is the salvation of ions and ______ is the current conducted by ions.

FILL IN THE BLANKS TYPE QUESTIONS | Q 6. | Page 205

The properties of an electrolytic solution are the properties of ______ present in the solution.

FILL IN THE BLANKS TYPE QUESTIONS | Q 7. | Page 205

The degree of dissociation of a weak electrolyte is ______ proportional to the ______ of its molar concentration.

FILL IN THE BLANKS TYPE QUESTIONS | Q 8. | Page 205

According to Ohm’s law, the potential difference across a conductor is ______ proportional to the ______ flowing through it.

FILL IN THE BLANKS TYPE QUESTIONS | Q 9. | Page 205

The unit of conductance is ______ which is also expressed as ______.

FILL IN THE BLANKS TYPE QUESTIONS | Q 10. | Page 205

Equivalent conductivity is the conducting power of all the ions furnished by one ______ of an electrolyte present in a definite ______ of the solution.

FILL IN THE BLANKS TYPE QUESTIONS | Q 11. | Page 205

D.C. cannot be used to measure the electrical conductivity of an electrolytic solution because it causes ______ effect.

FILL IN THE BLANKS TYPE QUESTIONS | Q 12. | Page 205

Conductivity water has a very ______ conductance.

FILL IN THE BLANKS TYPE QUESTIONS | Q 13. | Page 205

According to Debye-Huckel-Onsagar equation, `Lambda_m = Lambda_m^infty -` ______.

FILL IN THE BLANKS TYPE QUESTIONS | Q 14. | Page 205

The molar conductivity of a weak electrolytic solution is much ______ than that of a strong electrolytic solution.

FILL IN THE BLANKS TYPE QUESTIONS | Q 15. | Page 205

The salt bridge used in a galvanic cell completes the ______ and maintains the ______ of the solutions present in the two ______.

FILL IN THE BLANKS TYPE QUESTIONS | Q 16. | Page 205

While representing a galvanic cell, the oxidation electrode is always written at the ______ while the reduction electrode at the ______.

FILL IN THE BLANKS TYPE QUESTIONS | Q 17. | Page 205

The electrode potential of a standard hydrogen electrode is ______.

FILL IN THE BLANKS TYPE QUESTIONS | Q 18. | Page 205

When a SHE is connected to a Zn2+/Zn electrode, the electrons flow from ______ electrode to the ______ electrode and the current flows in the ______ direction.

FILL IN THE BLANKS TYPE QUESTIONS | Q 19. | Page 205

The electrode systems having positive values of standard electrode potentials act as ______ when connected to a standard hydrogen electrode.

FILL IN THE BLANKS TYPE QUESTIONS | Q 20. | Page 205

F2 is the ______ oxidising agent because it possesses the ______ value of standard electrode potential.

FILL IN THE BLANKS TYPE QUESTIONS | Q 21. | Page 205

A metal can displace any other metal placed ______ it in the electrochemical series from its salt solution.

FILL IN THE BLANKS TYPE QUESTIONS | Q 22. | Page 205

A cell reaction is feasible when the EMF of the cell is ______.

FILL IN THE BLANKS TYPE QUESTIONS | Q 23. | Page 205

The cell which converts ______ energy into ______ energy is called an electrolytic cell.

FILL IN THE BLANKS TYPE QUESTIONS | Q 24. | Page 206

The electrolysis of fused sodium chloride gives ______ at the cathode and ______ at the anode, whereas the products obtained on electrolysis of an aqueous solution of sodium chloride are ______ at the cathode and ______ at the anode.

FILL IN THE BLANKS TYPE QUESTIONS | Q 25. | Page 206

During the electrolysis of an aqueous solution of sodium chloride, the chloride ions get oxidised at anode in preference to water due to ______.

FILL IN THE BLANKS TYPE QUESTIONS | Q 26. | Page 206

If the cation produced from the electrolyte has higher reduction potential than that of water, the ______ will get reduced at the cathode.

FILL IN THE BLANKS TYPE QUESTIONS | Q 27. | Page 206

The electrochemical equivalent is the amount of substance liberated by a current of ______ ampere passed for ______ second.

FILL IN THE BLANKS TYPE QUESTIONS | Q 28. | Page 206

The quantity of electricity required to liberate one equivalent of any substance is ______ Faraday.

FILL IN THE BLANKS TYPE QUESTIONS | Q 29. | Page 206

Reduction of 1 mole of \[\ce{MnO^-_4}\] to Mn2+ requires ______ coulombs of charge.

FILL IN THE BLANKS TYPE QUESTIONS | Q 30. | Page 206

The cell potential of a dry cell is approximately ______ V to ______ V.

ASSERTION-REASON TYPE QUESTIONS [Page 206]

Nootan solutions for Chemistry Part 1 and 2 [English] Class 12 ISC 3 Electrochemistry ASSERTION-REASON TYPE QUESTIONS [Page 206]

ASSERTION-REASON TYPE QUESTIONS | Q 1. | Page 206

Assertion: When a Zn | Zn2+ electrode is connected to a standard hydrogen electrode, the electrons flow from zinc electrode to the hydrogen electrode.

Reason: The standard reduction potential of zinc electrode is lower than that of hydrogen electrode.

  • If both Assertion and Reason are CORRECT and Reason is the CORRECT explanation of the Assertion.

  • If both Assertion and Reason are CORRECT but Reason is not the CORRECT explanation of the Assertion.

  • If Assertion is CORRECT but Reason is INCORRECT.

  • If Assertion is INCORRECT but Reason is CORRECT.

ASSERTION-REASON TYPE QUESTIONS | Q 2. | Page 206

Assertion: The specific conductivity of an electrolytic solution decreases with increase in dilution.

Reason: Specific conductivity is the conductance due to the ions present in 1 cm3 of the solution.

  • If both Assertion and Reason are CORRECT and Reason is the CORRECT explanation of the Assertion.

  • If both Assertion and Reason are CORRECT but Reason is not the CORRECT explanation of the Assertion.

  • If Assertion is CORRECT but Reason is INCORRECT.

  • If Assertion is INCORRECT but Reason is CORRECT.

ASSERTION-REASON TYPE QUESTIONS | Q 3. | Page 206

Assertion: The electrode potential of a standard hydrogen electrode is equal to zero.

Reason: The value has been obtained on the basis of experimental observations.

  • If both Assertion and Reason are CORRECT and Reason is the CORRECT explanation of the Assertion.

  • If both Assertion and Reason are CORRECT but Reason is not the CORRECT explanation of the Assertion.

  • If Assertion is CORRECT but Reason is INCORRECT.

  • If Assertion is INCORRECT but Reason is CORRECT.

ASSERTION-REASON TYPE QUESTIONS | Q 4. | Page 206

Assertion: Copper can displace zinc from the solution of zinc sulphate.

Reason: Copper is placed below zinc in the electrochemical series.

  • If both Assertion and Reason are CORRECT and Reason is the CORRECT explanation of the Assertion.

  • If both Assertion and Reason are CORRECT but Reason is not the CORRECT explanation of the Assertion.

  • If Assertion is CORRECT but Reason is INCORRECT.

  • If Assertion is INCORRECT but Reason is CORRECT.

ASSERTION-REASON TYPE QUESTIONS | Q 5. | Page 206

Assertion: When \[\ce{E{^{\circ}_{cell}}}\] is positive, the cell reaction is feasible and proceeds spontaneously.

Reason: When \[\ce{E{^{\circ}_{cell}}}\] is positive, ΔG° is negative which makes the cell reaction feasible.

  • If both Assertion and Reason are CORRECT and Reason is the CORRECT explanation of the Assertion.

  • If both Assertion and Reason are CORRECT but Reason is not the CORRECT explanation of the Assertion.

  • If Assertion is CORRECT but Reason is INCORRECT.

  • If Assertion is INCORRECT but Reason is CORRECT.

NUMERICAL PROBLEMS [Pages 206 - 207]

Nootan solutions for Chemistry Part 1 and 2 [English] Class 12 ISC 3 Electrochemistry NUMERICAL PROBLEMS [Pages 206 - 207]

NUMERICAL PROBLEMS | Q 1. | Page 206

When a conductivity cell was filled with 0.02 M KCl, it had a resistance of 82.4 ohm at 25°C and when filled with 0.005 N K2SO4 it had a resistance of 326 ohm. Calculate

  1. cell constant
  2. specific conductivity, and
  3. equivalent conductivity of 0.005 N K2SO4 solution.

The specific conductance of 0.02 M KCl is 0.002768 ohm−1 cm−1.

NUMERICAL PROBLEMS | Q 2. | Page 206

The resistance of a 0.5 M solution of an electrolyte in a cell was found to be 45 ohm. Calculate the molar conductivity of the solution if the electrodes in the cell are 2.2 cm apart and have an area of 3.8 cm2.

NUMERICAL PROBLEMS | Q 3. | Page 206

During electrolysis, 4828.4 mg of iodine requires 3671.3 coulombs of electricity for its deposition at the anode. Calculate the value of Faraday’s constant.

NUMERICAL PROBLEMS | Q 4. | Page 207

Calculate the volume of Cl2 at STP produced during electrolysis of MgCl2 which produces 6.50 g of Mg. (At. wt. of Mg = 24.3)

NUMERICAL PROBLEMS | Q 5. | Page 207

A current of 1.70 amp is passed through 500 mL of 0.16 M solution of ZnSO4 for 230 seconds with a current efficiency of 90%. Find the molarity of Zn2+ after the deposition of zinc. Assume that the volume of the solution remains constant during electrolysis.

NUMERICAL PROBLEMS | Q 6. | Page 207

The reaction \[\ce{Zn_{(s)} + Co^{2+} -> Co_{(s)} + Zn^{2+}}\] occurs in a cell. Write the electrode reactions and compute the standard emf of the cell. 

Given that \[\ce{E^{\circ}_{{Zn/{Zn}^{2+}}}}\] = +0.76 V and \[\ce{E^{\circ}_{{Co/{Co}^{2+}}}}\] = 0.2 V.

NUMERICAL PROBLEMS | Q 7. | Page 207

There are two hydrogen electrodes in a cell. The anode is in contact with the hydrogen ion concentration of 10−6 M. The emf of the cell at 25°C is 0.118 volt. Calculate the hydrogen ion concentration at cathode.

NUMERICAL PROBLEMS | Q 8. | Page 207

How many grams of silver could be plated out on a serving tray by electrolysis of a solution containing silver in +1 oxidation state for a period of 8.0 hours at a current of 8.46 amperes? What is the area of the tray if the thickness of the silver plating is 0.00254 cm? Density of silver is 10.5 g cm−3.

NUMERICAL PROBLEMS | Q 9. | Page 207

Calculate the quantity of electricity required to reduce 6.15 g of nitrobenzene to aniline if the current efficiency is 68 per cent. If potential drop across the cell is 7.0 volts, calculate the energy consumed in the process.

NUMERICAL PROBLEMS | Q 10. (a) | Page 207

Calculate the pH of the following half cell solutions (at 25°C):

\[\ce{Pt, H2 (1 atm) | HCl; E_{H/H^+}}\] = 0.25 V

NUMERICAL PROBLEMS | Q 10. (b) | Page 207

Calculate the pH of the following half cell solutions (at 25°C):

\[\ce{Pt, H2 (1 atm) | H2SO; E_{H/H^+}}\] = 0.3 V

'NCERT TEXT-BOOK' Exercises [Pages 209 - 212]

Nootan solutions for Chemistry Part 1 and 2 [English] Class 12 ISC 3 Electrochemistry 'NCERT TEXT-BOOK' Exercises [Pages 209 - 212]

'NCERT TEXT-BOOK' Exercises | Q 3.1 | Page 209

Arrange the following metals in the order in which they displace each other from the solution of their salts.

Al, Cu, Fe, Mg and Zn.

'NCERT TEXT-BOOK' Exercises | Q 3.2 | Page 209

Given the standard electrode potentials,

K+/K = −2.93 V, Ag+/Ag = 0.80 V,

Hg2+/Hg = 0.79 V

Mg2+/Mg = −2.37 V, Cr3+/Cr = −0.74 V

Arrange these metals in their increasing order of reducing power.

'NCERT TEXT-BOOK' Exercises | Q 3.3 | Page 209

Depict the galvanic cell in which the reaction takes place.

\[\ce{Zn_{(s)} + 2Ag+_{ (aq)} -> Zn^{2+}_{ (aq)} + 2Ag_{(s)}}\]

Further show:

  1. Which of the electrode is negatively charged?
  2. The carriers of the current in the cell.
  3. Individual reaction at each electrode.
'NCERT TEXT-BOOK' Exercises | Q 3.4 (i) | Page 209

Calculate the standard cell potential of a galvanic cell in which the following reaction takes place:

\[\ce{2Cr_{(s)} + 3Cd{^{2+}_{(aq)}} -> 2Cr{^{3+}_{(aq)}} + 3Cd}\]

Calculate the ΔrG° and equilibrium constant of the reaction.

'NCERT TEXT-BOOK' Exercises | Q 3.4 (ii) | Page 209

Calculate the standard cell potential of a galvanic cell in which the following reaction takes place:

\[\ce{Fe{^{2+}_{(aq)}} + Ag{^{+}_{(aq)}} -> Fe{^{3+}_{(aq)}} + Ag_{(s)}}\]

Calculate the ΔrG° and equilibrium constant of the reaction.

'NCERT TEXT-BOOK' Exercises | Q 3.5 (i) | Page 210

Write the Nernst equation and emf of the following cell at 298 K:

Mg(s) | Mg2+ (0.001 M) || Cu2+ (0.0001 M) | Cu(s)

'NCERT TEXT-BOOK' Exercises | Q 3.5 (ii) | Page 210

Write the Nernst equation and emf of the following cell at 298 K:

Fe(s) | Fe2+ (0.001 M) || H+ (1 M) | H2(g) (1 bar) | Pt(s)

'NCERT TEXT-BOOK' Exercises | Q 3.5 (iii) | Page 210

Write the Nernst equation and emf of the following cell at 298 K:

\[\ce{Sn_{(s)} | Sn^{2+} (0.050 M) || H^+ (0.020 M) | H2_{(g)} (1 bar) | Pt_{(s)}}\]

'NCERT TEXT-BOOK' Exercises | Q 3.5 (iv) | Page 210

Write the Nernst equation and emf of the following cell at 298 K:

Pt(s) | Br (0.010 M) | Br2(l) || H+ (0.030 M) | H2(g) (1 bar) | Pt(s)

'NCERT TEXT-BOOK' Exercises | Q 3.6 | Page 210

In the button cells widely used in watches and other devices, the following reaction takes place:

\[\ce{Zn_{(s)} + Ag2O_{(s)} + H2O_{(l)} -> Zn{^{2+}_{(aq)}} + 2Ag_{(s)} + 2OH^-_{ (aq)}}\]

Determine ΔrG° and E° for the reaction.

'NCERT TEXT-BOOK' Exercises | Q 3.7 i. | Page 211

Define conductivity for the solution of an electrolyte.

'NCERT TEXT-BOOK' Exercises | Q 3.7 ii. | Page 211

Define “Molar conductivity”.

'NCERT TEXT-BOOK' Exercises | Q 3.7 iii. | Page 211

Discuss the variation of conductivity and molar conductivity with concentration.

'NCERT TEXT-BOOK' Exercises | Q 3.8 | Page 211

The conductivity of 0.20 M solution of KCl at 298 K is 0.0248 S cm−1. Calculate its molar conductivity.

'NCERT TEXT-BOOK' Exercises | Q 3.9 | Page 211

The resistance of a conductivity cell containing 0.001 M KCl solution at 298 K is 1500 Ω. What is the cell constant if the conductivity of 0.001 M KCl solution at 298 K is 0.146 × 10−3 S cm−1.

'NCERT TEXT-BOOK' Exercises | Q 3.10 | Page 210

The conductivity of sodium chloride at 298 K has been determined at different concentrations and the results are given below:

Concentration/M 0.001 0.010 0.020 0.050 0.100
102 × κ/S m−1 1.237 11.85 23.15 55.53 106.74

Calculate ∧m for all concentrations and draw a plot between ∧m and c1/2. Find the value of `∧_m^0`.

'NCERT TEXT-BOOK' Exercises | Q 3.11 | Page 211

Conductivity of 0.00241 M acetic acid is 7.896 × 10−5 S cm−1. Calculate its molar conductivity and if `∧_m^0` for acetic acid is 390.5 S cm2 mol−1, what is its dissociation constant?

'NCERT TEXT-BOOK' Exercises | Q 3.12 (i) | Page 211

How much charge is required for the following reduction:

1 mol of Al3+ to Al?

'NCERT TEXT-BOOK' Exercises | Q 3.12 (ii) | Page 211

How much charge is required for the following reduction? 

1 mol of Cu2+ to Cu.

'NCERT TEXT-BOOK' Exercises | Q 3.12 (iii) | Page 211

How much charge is required for the following reduction:

1 mol of \[\ce{MnO^-_4}\] to Mn2+?

'NCERT TEXT-BOOK' Exercises | Q 3.13 (i) | Page 211

How much electricity in terms of Faraday is required to produce 20 g of Ca from molten CaCl2?

(Given: Molar mass of Calcium is 40 g mol−1.)

'NCERT TEXT-BOOK' Exercises | Q 3.13 (ii) | Page 211

How much electricity in terms of Faraday is required to produce 40.0 g of Al from molten Al2O3?

(Given: Molar mass of Aluminium is 27 g mol−1.)

'NCERT TEXT-BOOK' Exercises | Q 3.14 (i) | Page 211

How much electricity is required in coulomb for the oxidation of 1 mol of H2O to O2?

'NCERT TEXT-BOOK' Exercises | Q 3.14 (ii) | Page 211

How much electricity is required in coulomb for the oxidation of 1 mol of FeO to Fe2O3?

'NCERT TEXT-BOOK' Exercises | Q 3.15 | Page 212

A solution of Ni(NO3)2 is electrolysed between platinum electrodes using a current of 5 amperes for 20 minutes. What mass of Ni is deposited at the cathode?

'NCERT TEXT-BOOK' Exercises | Q 3.16 | Page 212

Three electrolytic cells A, B, C containing solutions of ZnSO4, AgNO3 and CuSO4, respectively, are connected in series. A steady current of 1.5 amperes was passed through them until 1.45 g of silver deposited at the cathode of cell B. How long did the current flow? What mass of copper and zinc were deposited?

'NCERT TEXT-BOOK' Exercises | Q 3.17 (i) | Page 212

Using the standard electrode potentials, predict if the reaction between the following is feasible:

\[\ce{Fe^{3+}_{ (aq)}}\] and \[\ce{I^-_{ (aq)}}\]

'NCERT TEXT-BOOK' Exercises | Q 3.17 (ii) | Page 212

Using the standard electrode potentials, predict if the reaction between the following is feasible: 

\[\ce{Ag{^{+}_{(aq)}}}\] and Cu(aq)

'NCERT TEXT-BOOK' Exercises | Q 3.17 (iii) | Page 212

Using the standard electrode potentials, predict if the reaction between the following is feasible:

\[\ce{Fe^{3+}_{ (aq)}}\] and \[\ce{Br^-_{ (aq)}}\]

'NCERT TEXT-BOOK' Exercises | Q 3.17 (iv) | Page 212

Using the standard electrode potential, predict if the reaction between the following is feasible:

Ag(s) and \[\ce{Fe^{3+}_{ (aq)}}\]

'NCERT TEXT-BOOK' Exercises | Q 3.17 (v) | Page 212

Using the standard electrode potential, predict if the reaction between the following is feasible:

Br2(aq) and \[\ce{Fe^{2+}_{ (aq)}}\]

'NCERT TEXT-BOOK' Exercises | Q 3.18 (i) | Page 212

Predict the product of electrolysis in the following:

An aqueous solution of AgNO3 with silver electrodes.

'NCERT TEXT-BOOK' Exercises | Q 3.18 (ii) | Page 212

Predict the product of electrolysis in the following:

An aqueous solution of AgNOwith platinum electrodes.

'NCERT TEXT-BOOK' Exercises | Q 3.18 (iii) | Page 212

Predict the product of electrolysis in the following:

A dilute solution of H2SO4 with platinum electrodes.

'NCERT TEXT-BOOK' Exercises | Q 3.18 (iv) | Page 212

Predict the product of electrolysis in the following:

An aqueous solution of CuCl2 with platinum electrodes.

QUESTIONS FROM ISC EXAMINATION PAPERS [Pages 213 - 216]

Nootan solutions for Chemistry Part 1 and 2 [English] Class 12 ISC 3 Electrochemistry QUESTIONS FROM ISC EXAMINATION PAPERS [Pages 213 - 216]

QUESTIONS FROM ISC EXAMINATION PAPERS | Q 1. | Page 213

Correct the following statement:

Copper displaces both zinc and silver from their solutions.

QUESTIONS FROM ISC EXAMINATION PAPERS | Q 2. | Page 213

A conductivity cell has a cell constant of 0.5 cm−1. This cell when filled with 0.01 M sodium chloride solution, has a resistance of 384 ohms at 25°C. Calculate the equivalent conductivity of 0.01 M sodium chloride at 25°C.

QUESTIONS FROM ISC EXAMINATION PAPERS | Q 3. | Page 213

For the cell, Cu | Cu2+ (0.13 M) || Ag+ (0.01 M) | Ag,

  1. Calculate the reduction potential of each electrode if the standard reduction potential for copper and silver electrodes are 0.34 V and 0.80 V respectively.
  2. Calculate the emf of the cell.
  3. Write the cell reaction.
  4. Is this cell reaction spontaneous? Why?
QUESTIONS FROM ISC EXAMINATION PAPERS | Q 4. | Page 213

Correct the following statement:

For a strong electrolyte, the plot of equivalent conductance versus concentration of the solution is a straight line.

QUESTIONS FROM ISC EXAMINATION PAPERS | Q 5. | Page 213

A current of 4 amperes is passed through a molten solution for 45 minutes. 2.977 g of metal is deposited. Calculate the charge carried by the metal cation if its atomic mass is 106.4 g mol−1.

Fill in the blanks:

QUESTIONS FROM ISC EXAMINATION PAPERS | Q 6. | Page 213

As concentration of an electrolyte solution increases, its ______ conductance increases but ______ conductance decreases.

QUESTIONS FROM ISC EXAMINATION PAPERS | Q 7. | Page 213

A cell is constructed by dipping a zinc rod in 0.1 M zinc nitrate solution and a lead rod in 0.2 M lead nitrate solution.

\[\ce{E^{\circ}_{Pb^{2+}/Pb}}\] = −0.13 V and \[\ce{E^{\circ}_{Zn^{2+}/Zn}}\] = −0.76 V

  1. Write the spontaneous cell reaction.
  2. Calculate standard emf and emf of the cell.
QUESTIONS FROM ISC EXAMINATION PAPERS | Q 8. | Page 213

The number of Faradays which will be required to reduce 4 gram equivalents of Cu2+ to Cu metal is ______.

  • 1

  • 2

  • 3

  • 4

QUESTIONS FROM ISC EXAMINATION PAPERS | Q 9. | Page 213

For the cell:

Zn | Zn2+ (a = 1) || Cu2+ (a = 1) | Cu

Given that \[\ce{E^{\circ}_{Zn/Zn^{2+}}}\] = 0.761 volt; \[\ce{E^{\circ}_{Cu^{2+}/Cu}}\] = +0.339 volt

  1. Write the cell reaction.
  2. Calculate the emf and free energy change at 298 K involved in the cell.

[Faraday’s constant, F = 96500 coulomb mol−1]

QUESTIONS FROM ISC EXAMINATION PAPERS | Q 10. | Page 213

Calculate the equivalent conductivity of 1 M H2SO4, whose specific conductivity is 26 × 10−2 ohm−1 cm−1.

QUESTIONS FROM ISC EXAMINATION PAPERS | Q 11. (a) | Page 213

A current of 10 A is passed for 80 min. and 27 seconds through a cell containing dilute sulphuric acid.

  1. How many moles of oxygen gas will be liberated at the anode?
  2. Calculate the amount of zinc deposited at the cathode when another cell containing ZnSO4 solution is connected in series (Zn = 65).
QUESTIONS FROM ISC EXAMINATION PAPERS | Q 11. (b) | Page 213

Calculate:

Ecell at 25°C for the reaction:

\[\ce{Zn + Cu{^{2+}} (0.20 M) -> Zn{^{2+}} (0.50 M) + Cu}\]

Given: \[\ce{E^{\circ}_{({Zn^{2+}/{Zn}})}}\] = −0.76 volt, \[\ce{E^{\circ}_{({Cu^{2+}/{Cu}})}}\] = 0.34 volt

QUESTIONS FROM ISC EXAMINATION PAPERS | Q 11. (c) | Page 213

Give a reason for the following:

Specific conductance decreases with dilution, whereas equivalent conductance increases with dilution.

Complete the following sentence by selecting the correct alternative from the choice given:

QUESTIONS FROM ISC EXAMINATION PAPERS | Q 12. (a) | Page 214

When zinc granule is dipped in copper sulphate solution, copper is precipitated because ______.

  • Both copper and zinc have a positive reduction potential.

  • Reduction potential of copper is higher than that of zinc.

  • Reduction potential of zinc is higher than that of copper.

  • Both zinc and copper have a negative reduction potential.

fill in the blanks:

QUESTIONS FROM ISC EXAMINATION PAPERS | Q 12. (b) | Page 214

In a galvanic cell, the movement of electrons in the external circuit is from ______ to ______.

QUESTIONS FROM ISC EXAMINATION PAPERS | Q 12. (c) | Page 214

Zinc displaces hydrogen from acid solution (\[\ce{E^{\circ}_{Zn^{2+}/Zn}}\] = −0.76 V). Explain.

QUESTIONS FROM ISC EXAMINATION PAPERS | Q 12. (d) | Page 214

A 0.05 M NaOH solution offered a resistance of 31.6 ohms in a conductivity cell. If the cell constant of the conductivity cell is 0.378 cm−1, determine the molar conductivity of sodium hydroxide solution at this temperature.

QUESTIONS FROM ISC EXAMINATION PAPERS | Q 13. (a) | Page 214

Mention any two factors affecting the electrode potential of a metal.

QUESTIONS FROM ISC EXAMINATION PAPERS | Q 13. (b) | Page 214

For the following cell, calculate the emf:

\[\ce{Al | Al^{3+} (0.01 M) || Fe^{2+} (0.02 M) | Fe}\]

Given: \[\ce{E^{\circ}_{{Al^{3+}/{Al}}}}\] = −1.66 V, \[\ce{E^{\circ}_{{Fe^{2+}/{Fe}}}}\] = −0.44 V

QUESTIONS FROM ISC EXAMINATION PAPERS | Q 14. (a) | Page 214

When zinc granule is dipped in copper sulphate solution, copper is precipitated because ______.

  • Both copper and zinc have a positive reduction potential.

  • Reduction potential of copper is higher than that of zinc.

  • Reduction potential of zinc is higher than that of copper.

  • Both zinc and copper have a negative reduction potential.

QUESTIONS FROM ISC EXAMINATION PAPERS | Q 14. (b) | Page 214

State Faraday’s first law of electrolysis.

QUESTIONS FROM ISC EXAMINATION PAPERS | Q 14. (c) | Page 214

How many electrons will flow when a current of 5 amperes is passed through a solution for 200 seconds?

QUESTIONS FROM ISC EXAMINATION PAPERS | Q 15. | Page 214

Consider the reaction:

\[\ce{2Ag+ + Cd -> 2Ag + Cd^{2+}}\]

The reduction potentials of Ag+/Ag and Cd2+/Cd are +0.80 volt and −0.40 volt respectively.

  1. Give the cell representation.
  2. What is the standard cell emf, E°?
  3. What will be the emf of the cell if concentration of Cd2+ is 0.1 M and Ag+ is 0.2 M?
  4. Will the cell work spontaneously for the condition given in (c) above?

Fill in the blanks:

QUESTIONS FROM ISC EXAMINATION PAPERS | Q 16. (a) | Page 214

Zinc can displace ______ from CuSO4 solution, but cannot displace ______ from MgSO4 solution.

QUESTIONS FROM ISC EXAMINATION PAPERS | Q 16. (b) | Page 214

The quantity of electricity required to deposit 1.15 g of sodium from molten NaCl (Na = 23, Cl = 35.5) is ______.

  • 1 F

  • 0.5 F

  • 0.05 F

  • 1.5 F

QUESTIONS FROM ISC EXAMINATION PAPERS | Q 16. (c) | Page 214

The conductivity of 0.2 M KCl solution is 3 × 10−2 ohm−1 cm−1. Calculate its molar conductance.

QUESTIONS FROM ISC EXAMINATION PAPERS | Q 17. (a) | Page 214

Magnesium displaces hydrogen from dilute acid solution because ______.

  • The oxidation potential of magnesium is less than that of hydrogen.

  • The reduction potential of magnesium is less than that of hydrogen.

  • Both magnesium and hydrogen have same oxidation potential.

  • Both magnesium and hydrogen have same reduction potential.

QUESTIONS FROM ISC EXAMINATION PAPERS | Q 17. (b) | Page 214

Calculate the number of coulombs required to deposit 20.25 g of aluminium (at. mass = 27) from a solution containing Al+3.

QUESTIONS FROM ISC EXAMINATION PAPERS | Q 18. (a) i. | Page 214

What do you understand by specific conductance of a solution?

QUESTIONS FROM ISC EXAMINATION PAPERS | Q 18. (a) ii. | Page 214

What are the units of specific conductivity?

QUESTIONS FROM ISC EXAMINATION PAPERS | Q 18. (a) iii. | Page 214

How is equivalent conductivity related to specific conductivity?

QUESTIONS FROM ISC EXAMINATION PAPERS | Q 18. (b) | Page 214

2.5 amperes of current is passed through copper sulphate solution for 30 minutes. Calculate the number of copper atoms deposited at the cathode (Cu = 63.54).

QUESTIONS FROM ISC EXAMINATION PAPERS | Q 18. (c) | Page 214

Four metals W, X, Y and Z have the following values of Ered:

Ered

W = −0.140 V 

X = −2.93 V 

Y = +0.80 V

Z = +1.50 V

Arrange them in the increasing order of reducing power.

QUESTIONS FROM ISC EXAMINATION PAPERS | Q 19. | Page 214

A current liberates 0.50 g of hydrogen in 2 hours. The weight of copper (at. wt. = 63.5) deposited at the same time by the same current through copper sulphate solution is ______.

  • 63.5 g

  • 31.8 g

  • 15.9 g

  • 15.5 g

QUESTIONS FROM ISC EXAMINATION PAPERS | Q 20. | Page 214

What happens when a nickel rod is dipped into a copper sulphate solution? Justify your answer.

[\[\ce{E{^{\circ}_{Ni^{+2}/Ni}}}\] = − 0.25 V and \[\ce{E{^{\circ}_{Cu^{+2}/Cu}}}\] = +0.34 V]

QUESTIONS FROM ISC EXAMINATION PAPERS | Q 21. (a) | Page 214

What is standard hydrogen electrode?

QUESTIONS FROM ISC EXAMINATION PAPERS | Q 21. (b) | Page 214

0.05 M NaOH solution offered resistance of 31.6 ohms in a conductivity cell at 298 K. If the cell constant of the cell is 0.367 cm−1, calculate the molar conductivity of the NaOH solution.

QUESTIONS FROM ISC EXAMINATION PAPERS | Q 22. | Page 214

0.3605 g of a metal is deposited on the electrode by passing 1.2 amperes of current for 15 minutes through its salt solution. The atomic weight of the metal is 96. What is the valency of the metal?

QUESTIONS FROM ISC EXAMINATION PAPERS | Q 23. | Page 214

How many hours does it take to reduce 3 moles of Fe3+ to Fe2+ with 2.0 A current intensity?

QUESTIONS FROM ISC EXAMINATION PAPERS | Q 24. | Page 214

The specific conductance of a 0.01 M solution of acetic acid at 298 K is 1.65 × 10−4 ohm1 cm1. The molar conductance at infinite dilution for H+ ion and CH3COO ion is 349.1 ohm1 cm2 mol1 and 40.9 ohm1 cm2 mol1 respectively.

Calculate:

  1. Molar conductance of the solution.
  2. The degree of dissociation of CH3COOH.
  3. A dissociation constant for acetic acid.
QUESTIONS FROM ISC EXAMINATION PAPERS | Q 25. | Page 215

Calculate the e.m.f. of the following cell reaction at 298 K:

\[\ce{Mg_{(s)} + Cu{^{2+}} (0.0001 M) -> Mg{^{2+}} (0.001M) + Cu_{(s)}}\]

The standard potential (E°) of the cell is 2.71 V.

QUESTIONS FROM ISC EXAMINATION PAPERS | Q 26. | Page 215

Consider the following cell reaction at 298 K:

\[\ce{2Ag+ + Cd -> 2Ag + Cd^{2+}}\]

The standard reduction potentials (E°) for Ag+/Ag and Cd2+/Cd are 0.80 V and −0.40 V respectively.

  1. Write the cell representation.
  2. What will be the emf of the cell if concentration of Cd2+ is 0.1 M and that of Ag+ is 0.2 M?
  3. Will the cell work spontaneously for the condition given in (b) above?
QUESTIONS FROM ISC EXAMINATION PAPERS | Q 27. | Page 215

A 0.05 M NH4OH solution offers the resistance of 50 ohms to a conductivity cell at 298 K. If the cell constant is 0.50 cm−1 and molar conductance of NH4OH at infinite dilution is 471.4 ohm−1 cm2 mol−1, calculate:

  1. Specific conductance
  2. Molar conductance
  3. Degree of dissociation

Fill in the blanks:

QUESTIONS FROM ISC EXAMINATION PAPERS | Q 28. (a) | Page 215

On dilution of a solution, its specific conductance ______ while its equivalent conductance ______.

QUESTIONS FROM ISC EXAMINATION PAPERS | Q 28. (b) | Page 215

More ______ the standard reduction potential of a substance, the ______ is its ability to displace hydrogen from acids.

QUESTIONS FROM ISC EXAMINATION PAPERS | Q 29. | Page 215

For a spontaneous reaction ΔG° and \[\ce{E{^{\circ}_{cell}}}\] will be respectively:

  • −ve and +ve

  • +ve and −ve

  • +ve and +ve

  • −ve and −ve

QUESTIONS FROM ISC EXAMINATION PAPERS | Q 30. | Page 215

Specific conductivity of 0.20 M solution of KCl at 298 K is 0.025 S cm−1. Calculate its molar conductivity.

QUESTIONS FROM ISC EXAMINATION PAPERS | Q 31. (a) (i) | Page 215

The following electrochemical cell is set up at 298 K:

\[\ce{Zn | Zn^{2+}_{ (aq)} (1 M) || Cu^{2+}_{ (aq)} (1 M) | Cu}\]

Given: \[\ce{E^{\circ}_{Zn^{2+}/Zn}}\] = −0.761 V, \[\ce{E^{\circ}_{Cu^{2+}/Cu}}\] = +0.339 V

Write the cell reaction.

QUESTIONS FROM ISC EXAMINATION PAPERS | Q 31. (a) (ii) | Page 215

The following electrochemical cell is set up at 298 K: 

\[\ce{Zn | Zn^{2+}_{ (aq)} (1 M) || Cu^{2+}_{ (aq)} (1 M) | Cu}\]

Given: \[\ce{E^{\circ}_{Zn^{2+}/Zn}}\] = −0.761 V, \[\ce{E^{\circ}_{Cu^{2+}/Cu}}\] = +0.339 V

Calculate the emf and free energy change at 298 K.

Answer the following:

QUESTIONS FROM ISC EXAMINATION PAPERS | Q 31. (b) (i) | Page 215

What is the effect of temperature on the ionic product of water (Kw)?

QUESTIONS FROM ISC EXAMINATION PAPERS | Q 31. (b) (ii) | Page 215

What happens to the ionic product of water (Kw) if some acid is added to it?

QUESTIONS FROM ISC EXAMINATION PAPERS | Q 32. | Page 215

Name the law or principle to which the following observations confirm:

When 9650 coulombs of electricity is passed through a solution of copper sulphate, 3.175 g of copper is deposited on the cathode (at. wt. of Cu = 63.5).

Fill in the blanks:

QUESTIONS FROM ISC EXAMINATION PAPERS | Q 33. | Page 215

A galvanic cell converts ______ energy into ______ energy.

QUESTIONS FROM ISC EXAMINATION PAPERS | Q 34. (a) | Page 215

Calculate the emf and ΔG° for the cell reaction at 25°C:

\[\ce{\underset{(0.1 M)}{Zn_{(s)} | Zn^{2+}_{ (aq)}} || \underset{(0.01 M)}{Cd^{2+}_{ (aq)} | Cd_{(s)}}}\]

Given \[\ce{E^{\circ}_{Zn^{2+}/Zn}}\] = −0.763 and \[\ce{E^{\circ}_{Cd^{2+}/Cd}}\] = −0.403

QUESTIONS FROM ISC EXAMINATION PAPERS | Q 34. (b) (i) | Page 215

Define the term equivalent conductance.

QUESTIONS FROM ISC EXAMINATION PAPERS | Q 34. (b) (ii) | Page 215

Define the following term:

Corrosion of metals

QUESTIONS FROM ISC EXAMINATION PAPERS | Q 35. (a) | Page 215

The specific conductivity of a solution containing 5 g of anhydrous BaCl2 (mol. wt. = 208) in 1000 cm3 of a solution is found to be 0.0058 ohm−1 cm1. Calculate the molar and equivalent conductivity of the solution.

QUESTIONS FROM ISC EXAMINATION PAPERS | Q 35. (b) i. | Page 215

What do you understand by electrochemical series?

QUESTIONS FROM ISC EXAMINATION PAPERS | Q 35. (b) ii. | Page 215

How is the electrochemical series useful in predicting whether a metal can liberate hydrogen from acid or not?

QUESTIONS FROM ISC EXAMINATION PAPERS | Q 36. (i) | Page 215

Calculate the mass of silver deposited at cathode when a current of 2 amperes is passed through a solution of AgNO3 for 15 minutes.

(at. wt. of Ag = 108, 1 F = 96500 C)

QUESTIONS FROM ISC EXAMINATION PAPERS | Q 36. (ii) | Page 215

Calculate the emf and ΔG for the cell reaction at 298 K:

Mg(s) | Mg2+ (0.1 M) || Cu2+ (0.01 M) | Cu(s)

Given: \[\ce{E^{\circ}_{cell}}\] = 2.71 V

1 F = 96500 C

QUESTIONS FROM ISC EXAMINATION PAPERS | Q 37. (i) (a) | Page 215

Define the following term:

Specific conductance

QUESTIONS FROM ISC EXAMINATION PAPERS | Q 37. (i) (b) | Page 215

Define the following term:

Kohlrausch’s Law.

QUESTIONS FROM ISC EXAMINATION PAPERS | Q 37. (ii) | Page 215

The resistance of a conductivity cell containing 0.001 M KCl solution at 298 K is 1500 ohm. What is the cell constant and molar conductivity of 0.001 M KCl solution, if the conductivity of this solution is 0.146 × 10−3 ohm−1 cm−1 at 298 K?

QUESTIONS FROM ISC EXAMINATION PAPERS | Q 38. | Page 215

Calculate the molar conductivity at infinite dilution for CH3COOH if the molar conductivity at infinite dilution for NaCl, HCl and CH3COONa are 126.45, 426.16 and 91.0 ohm−1 cm2 mol−1 respectively.

QUESTIONS FROM ISC EXAMINATION PAPERS | Q 39. | Page 215

Calculate the emf and ΔG for the given cell at 25°C:

Cr(s) | Cr3+ (0.1 M) || Fe2+ (0.01 M) || Fe(s)

Given: \[\ce{E^{\circ}_{Cr^{3+}/Cr}}\] = −0.74 V, \[\ce{E^{\circ}_{Fe^{2+}/Fe}}\] = −0.44 V

(1 F = 96500 C mol−1, R = 8.314 JK−1 mol−1)

QUESTIONS FROM ISC EXAMINATION PAPERS | Q 40. | Page 216

Calculate the degree of dissociation (α) of acetic acid if its molar conductivity (Λm) is 39.05 S cm2 mol−1.

(Given \[\ce{\lambda^{\circ}_{(H^+)}}\] = 349.6 S cm2 mol−1 and \[\ce{\lambda^{\circ}_{(CH_3COO^-)}}\] = 40.95 S cm2 mol−1)

Select and write the correct alternative from the choices given below:

QUESTIONS FROM ISC EXAMINATION PAPERS | Q 41. (i) | Page 216

Which of the following statements is true for electrochemical cell?

  • Cations move towards zinc electrode.

  • Cations move towards copper electrode.

  • Current flows from zinc electrode to copper electrode.

  • Electrons flow from copper electrode to zinc electrode.

QUESTIONS FROM ISC EXAMINATION PAPERS | Q 41. (ii) | Page 216

Electrochemical equivalent (z) is the amount of substance which gets deposited from its solutions on passing electrical charge equal to solutions on passing electrical charge equal to ______.

  • 96500 coulombs

  • 9650 coulombs

  • 965 coulombs

  • 1 coulomb

QUESTIONS FROM ISC EXAMINATION PAPERS | Q 41. (iii) | Page 216

The standard electrode potential of Cu+2/Cu is +0.34 V and that of Cr+3/Cr is −0.74 V. These two electrodes are connected in their standard state to make an electrochemical cell. What will be the standard electrode potential (E°) of this cell?

  • 1.19 V

  • 1.08 V

  • 0.69 V

  • 1.83 V

QUESTIONS FROM ISC EXAMINATION PAPERS | Q 41. (iv) | Page 216

The ionic conductance at infinite dilution for Ba+2 and Cl ions are 127 ohm−1 cm2 mol−1 and 76 ohm−1 cm2 mol−1 respectively. What will be the molar conductance of BaCl2 at infinite dilution?

  • 139.5 ohm−1 cm2 mol−1

  • 279.0 ohm−1 cm2 mol−1

  • 203.0 ohm−1 cm2 mol−1

  • 101.5 ohm−1 cm2 mol−1

QUESTIONS FROM ISC EXAMINATION PAPERS | Q 41. (v) 1. | Page 216

A conductivity cell is filled with 0.05 M NaOH solution offering a resistance of 31.6 ohm. If the cell constant of the cell is 0.347 cm−1, calculate the following:

The value of specific conductance:

  • 1.29 × 10−4 ohm−1 cm−1

  • 12.9 × 10−4 ohm−1 cm−1

  • 1.16 × 10−2 ohm−1 cm−1

  • 11.6 × 10−2 ohm−1 cm−1

QUESTIONS FROM ISC EXAMINATION PAPERS | Q 41. (v) 2. | Page 216

A conductivity cell is filled with 0.05 M NaOH solution offering a resistance of 31.6 ohm. If the cell constant of the cell is 0.347 cm−1, calculate the following:

The value of molar conductance:

  • 232.20 ohm−1 cm2 mol−1

  • 23.22 ohm−1 cm2 mol−1

  • 119.07 ohm−1 cm2 mol−1

  • 165.36 ohm−1 cm2 mol−1

QUESTIONS FROM ISC EXAMINATION PAPERS | Q 41. (vi) 1. | Page 216

The standard electrode potential for Sn+4/Sn+2 couple is +0.15 V and that for the Cr+3/Cr couple is −0.74 V. These two couples in their standard states are connected to make a cell (1 Faraday = 96500 mol−1)

What will be the value of \[\ce{E{^{\circ}_{cell}}}\]?

  • +1.19 V

  • +0.89 V

  • +0.18 V

  • +1.83 V

QUESTIONS FROM ISC EXAMINATION PAPERS | Q 41. (vi) 2. | Page 216

The standard electrode potential for Sn+4/Sn+couple is +0.15 V and that for the Cr+3/Cr couple is −0.74 V. These two couples in their standard states are connected to make a cell. (1 Faraday = 96500 mol−1)

What will be the value of standard Gibbs energy (ΔG°)?

  • −650.3 kJ

  • −515.3 kJ

  • −226.4 kJ

  • −406.8 kJ

QUESTIONS FROM ISC EXAMINATION PAPERS | Q 41. (vii) 1. | Page 216

A solution containing 2 g of anhydrous barium chloride in 400 cm3 of water has a specific conductivity of 0.0058 S cm−1. (at. wt. of Ba = 137, Cl = 35.5)

What is the molarity of the above solution?

  • 0.204 M

  • 0.024 M

  • 0.420 M

  • 4.021 M

QUESTIONS FROM ISC EXAMINATION PAPERS | Q 41. (vii) 2. | Page 216

A solution containing 2 g of anhydrous barium chloride in 400 cm3 of water has a specific conductivity of 0.0058 S cm−1. (at. wt. of Ba = 137, Cl = 35.5)

What is the molar conductivity of the above solution?

  • 241.67 S cm2/mol

  • 261.47 S cm2/mol

  • 247.17 S cm2/mol

  • 361.47 S cm2/mol

Solutions for 3: Electrochemistry

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Nootan solutions for Chemistry Part 1 and 2 [English] Class 12 ISC chapter 3 - Electrochemistry - Shaalaa.com

Nootan solutions for Chemistry Part 1 and 2 [English] Class 12 ISC chapter 3 - Electrochemistry

Shaalaa.com has the CISCE Mathematics Chemistry Part 1 and 2 [English] Class 12 ISC CISCE solutions in a manner that help students grasp basic concepts better and faster. The detailed, step-by-step solutions will help you understand the concepts better and clarify any confusion. Nootan solutions for Mathematics Chemistry Part 1 and 2 [English] Class 12 ISC CISCE 3 (Electrochemistry) include all questions with answers and detailed explanations. This will clear students' doubts about questions and improve their application skills while preparing for board exams.

Further, we at Shaalaa.com provide such solutions so students can prepare for written exams. Nootan textbook solutions can be a core help for self-study and provide excellent self-help guidance for students.

Concepts covered in Chemistry Part 1 and 2 [English] Class 12 ISC chapter 3 Electrochemistry are Overview of Electrochemistry.

Using Nootan Chemistry Part 1 and 2 [English] Class 12 ISC solutions Electrochemistry exercise by students is an easy way to prepare for the exams, as they involve solutions arranged chapter-wise and also page-wise. The questions involved in Nootan Solutions are essential questions that can be asked in the final exam. Maximum CISCE Chemistry Part 1 and 2 [English] Class 12 ISC students prefer Nootan Textbook Solutions to score more in exams.

Get the free view of Chapter 3, Electrochemistry Chemistry Part 1 and 2 [English] Class 12 ISC additional questions for Mathematics Chemistry Part 1 and 2 [English] Class 12 ISC CISCE, and you can use Shaalaa.com to keep it handy for your exam preparation.

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