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

Assertion: Mercury cell does not give steady potential. Reason: In the cell reaction, ions are not involved in solution.

Advertisements
Advertisements

प्रश्न

Assertion: Mercury cell does not give steady potential.

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

विकल्प

  • Both assertion and reason are true and the reason is the correct explanation of assertion.

  • Both assertion and reason are true and the reason is not the correct explanation of assertion.

  • Assertion is true but the reason is false.

  • Both assertion and reason are false.

  • Assertion is false but reason is true.

MCQ
Advertisements

उत्तर

Assertion is false but reason is true.

Explanation:

Mercury cell gives a steady potential because in the cell reaction ions are not involved in the solution.

shaalaa.com
  क्या इस प्रश्न या उत्तर में कोई त्रुटि है?
अध्याय 3: Electrochemistry - Exercises [पृष्ठ ४२]

APPEARS IN

एनसीईआरटी एक्झांप्लर Chemistry Exemplar [English] Class 12
अध्याय 3 Electrochemistry
Exercises | Q V. 60. | पृष्ठ ४२

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?


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.


How many electrons flow through a metllic wire if a current of 0·5 A is passed for 2 hours? (Given : 1 F = 96,500 C mol−1)


cell for the given redox reaction is 2.71 V
Mg(s) + Cu2+ (0.01 M) → Mg2+ (0.001 M) + Cu(s)

Calculate Ecell for the reaction. Write the direction of flow of current when an external opposite potential applied is
(i) less than 2.71 V and
(ii) greater than 2.71 V


Assertion: pure iron when heated in dry air is converted with a layer of rust.

Reason: Rust has the compositionFe3O4.


Define cathode


Describe the construction of Daniel cell. Write the cell reaction.


Why is anode in galvanic cell considered to be negative and cathode positive electrode?


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


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


`E_(cell)^Θ` = 1.1V for Daniel cell. Which of the following expressions are correct description of state of equilibrium in this cell?

(i) 1.1 = `K_c`

(ii) `(2.303RT)/(2F) logK_c` = 1.1

(iii) `log K_c = 2.2/0.059`

(iv) `log K_c` = 1.1


For the given cell, \[\ce{Mg | Mg^{2+} || Cu^{2+} | Cu}\]

(i) \[\ce{Mg}\] is cathode

(ii) \[\ce{Cu}\] is cathode

(iii) The cell reaction is \[\ce{Mg^+ Cu^{2+} -> Mg^{2+} + Cu}\]

(iv) \[\ce{Cu}\] is the oxidising agent


Can absolute electrode potential of an electrode be measured?


Consider the following diagram in which an electrochemical cell is coupled to an electrolytic cell. What will be the polarity of electrodes ‘A’ and ‘B’ in the electrolytic cell?


A current of 2.0 ampere passed for 5 hour through a molten salt deposits 22 g of the metal (Atomic mass = 177). The oxidation state of the metal in the metal salt is


Standard reduction electrode potentials of three metals A, B and C are respectively + 0.5 V, – 3.0 V. and – 1.2 V. The reducing powers of there metal is.


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)

The number of moles of electrons passed when the current of 2 A is passed through a solution of electrolyte for 20 minutes is ______.


The two half cell reaction of an electrochemical cell is given as 

\[\ce{Ag+ + e- -> Ag}\], `"E"_("Ag"^+//"Ag")^circ` = - 0.3995 V

\[\ce{Fe^{2+} -> Fe^{3+} + e-}\], `"E"_("Fe"^{3+}//"Fe")^{2+}` = - 0.7120 V

The value of EMF will be ______.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×