मराठी
कर्नाटक बोर्ड पी.यू.सी.पीयूसी विज्ञान 2nd PUC Class 12

Use the data given in below find out the most stable oxidised species. E0cr2O12-Cr3+ = 1.33 V E0Cl2Cl- = 1.36 V E0MnO4-MN2+ = 1.51 V E0Cr3+Cr = – 0.74 V

Advertisements
Advertisements

प्रश्न

Use the data given in below find out the most stable oxidised species.

`E^0 (Cr_2O_1^(2-))/(Cr_(3+))` = 1.33 V   `E^0 (Cl_2)/(Cl^-)` = 1.36 V

`E^0 (MnO_4^-)/(MN^(2+))` = 1.51 V   `E^0 (Cr^(3+))/(Cr)` = – 0.74 V

पर्याय

  • \[\ce{Cr^{3+}}\] 

  • \[\ce{MnO^{-}4}\]

  • \[\ce{CrO^{2-}7}\]

  • \[\ce{Mn^{2+}}\] 

MCQ
Advertisements

उत्तर

\[\ce{Cr^{3+}}\] 

Explanation:

 \[\ce{Cr^{3+}/Cr}\] has most negative value of standard reduction potential. Hence, \[\ce{Cr^{3+}}\]  is the most oxidized species.

shaalaa.com
  या प्रश्नात किंवा उत्तरात काही त्रुटी आहे का?
पाठ 3: Electrochemistry - Exercises [पृष्ठ ३५]

APPEARS IN

एनसीईआरटी एक्झांप्लर Chemistry Exemplar [English] Class 12
पाठ 3 Electrochemistry
Exercises | Q I. 12. | पृष्ठ ३५

संबंधित प्रश्‍न

What happens if external potential applied becomes greater than E°cell of electrochemical cell?


Can you store copper sulphate solutions in a zinc pot?


How many faradays of electricity are required to produce 6 g of Mg from MgCl2?


A solution of Cu(NO3)2 is electrolyzed between platinum electrodes using 0.1 Faraday electricity. How many moles of Cu will be deposited at the cathode?


At 25°C, the emf of the following electrochemical cell.

\[\ce{Ag_{(s)} | Ag^+ (0.01 M) | | Zn^{2+} {(0.1 M)} | Zn_{(s)}}\] will be:

(Given \[\ce{E^0_{cell}}\] = −1.562 V)


How many faradays of electricity are required for the following reaction to occur

\[\ce{MnO^-_4 -> Mn^2+}\]


A current strength of 3.86 A was passed through molten Calcium oxide for 41minutes and 40 seconds. The mass of Calcium in grams deposited at the cathode is (atomic mass of Ca is 40g/mol and 1F = 96500 C).


Define anode


Can Fe3+ oxidises bromide to bromine under standard conditions?

Given: \[\ce{E^0_{{Fe^{3+}|Fe^{2+}}}}\] = 0.771 V

\[\ce{E^0_{{Br_{2}|Br^-}}}\] = −1.09 V


Two metals M1 and M2 have reduction potential values of −xV and +yV respectively. Which will liberate H2 and H2SO4.


Electrode potential for Mg electrode varies according to the equation

`E_(Mg^(2+)  |  Mg) = E_(Mg^(2+)  |  Mg)^Θ - 0.059/2 log  1/([Mg^(2+)])`. The graph of `E_(Mg^(2+)  |  Mg)` vs `log [Mg^(2+)]` is ______.


The quantity of charge required to obtain one mole of aluminium from Al2O3 is ______.


What is electrode potential?


Match the terms given in Column I with the items given in Column II.

Column I Column II
(i) Λm (a) intensive property
(ii) ECell (b) depends on number of ions/volume
(iii) K (c) extensive property
(iv) ∆rGCell (d) increases with dilution

Assertion: ECell should have a positive value for the cell to function.

Reason: `"E"_("cathode") < "E"_("anode")`


Assertion: Mercury cell does not give steady potential.

Reason: In the cell reaction, ions are not involved in solution.


Read the passage given below and answer the questions that follow:

Oxidation-reduction reactions are commonly known as redox reactions. They involve transfer of electrons from one species to another. In a spontaneous reaction, energy is released which can be used to do useful work. The reaction is split into two half-reactions. Two different containers are used and a wire is used to drive the electrons from one side to the other and a Voltaic/Galvanic cell is created. It is an electrochemical cell that uses spontaneous redox reactions to generate electricity. A salt bridge also connects to the half-cells. The reading of the voltmeter gives the cell voltage or cell potential or electromotive force. If \[\ce{E^0_{cell}}\] is positive the reaction is spontaneous and if it is negative the reaction is non-spontaneous and is referred to as electrolytic cell. Electrolysis refers to the decomposition of a substance by an electric current. One mole of electric charge when passed through a cell will discharge half a mole of a divalent metal ion such as Cu2+. This was first formulated by Faraday in the form of laws of electrolysis.
The conductance of material is the property of materials due to which a material allows the flow of ions through itself and thus conducts electricity. Conductivity is represented by k and it depends upon nature and concentration of electrolyte, temperature, etc. A more common term molar conductivity of a solution at a given concentration is conductance of the volume of solution containing one mole of electrolyte kept between two electrodes with the unit area of cross-section and distance of unit length. Limiting molar conductivity of weak electrolytes cannot be obtained graphically.

  1. Is silver plate the anode or cathode?  (1)
  2. What will happen if the salt bridge is removed?  (1)
  3. When does electrochemical cell behaves like an electrolytic cell?  (1)
  4. (i) What will happen to the concentration of Zn2+ and Ag+ when Ecell = 0.   (1)
    (ii) Why does conductivity of a solution decreases with dilution?  (1)
    OR
    The molar conductivity of a 1.5 M solution of an electrolyte is found to be 138.9 S cm2mol-1. Calculate the conductivity of this solution.  (2)

What are electrochemical reactions?


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×