Electrochemistry Class 12 MCQs Questions with Answers

1. Standard solution of KNO3 is used to make a salt bridge because:

2. The emf of the cell:
Ni / Ni2+ (1.0 M) // Au3+ (1.0 M) / Au (E° = -0.25 V for Ni2+/Ni; E° = 1.5 V for Au3+/Au) is:

3. The emf of the cell:
Ni / Ni2+ (1.0 M) // Au3+ (1.0 M) / Au (E° = -0.25 V for Ni2+/Ni; E° = 1.5 V for Au3+/Au) is:

4. If E°Fe2+/Fe = -0.441 V and E°Fe2+/Fe2+ = 0.771 V, the standard EMF of the reaction,
Fe + 2Fe3+ → 3Fe2+ will be:

5. The E0M3+/M2+ values for Cr, Mn, Fe and Co are -0.41, + 1.57, + 0.77 and +1.97 V respectively. For which one of the metals, the change in oxidation state from +2 to +3 is easiest?

6. Faraday’s law of electrolysis is related to:

7. The standard reduction potentials of X, Y, Z metals are 0.52, -3.03, -1.18 respectively. The order of reducing power of the corresponding metals is:

8. The standard reduction potentials of Cu2+/Cu and Cu2+/Cu+ are 0.337 and 0.153 respectively. The standard electrode potential of Cu+/Cu half cell is:

9. 4.5 g of aluminium (at. mass 27 amu) is deposited at cathode from Al3+ solution by a certain quantity of electric charge. The volume of hydrogen produced at STP from H+ ions in solution by the same quantity of electric charge will be:

10. The reaction, 3ClO– (aq) → ClO3 (aq) + 2Cl– (aq) is an example of:

11. Units of the properties measured are given below. Which of the properties has been not matched correctly ?

12. For a certain redox reaction, E° is positive. This means that:

13.  Electrical conductance through metals is called metallic or electronic conductance and is due to the movement of electrons. The electronic conductance depends on:

14. A conductivity cell containing electrodes made up of:

15. The charge required for the reduction of 1 mol of MnO4– to MnO2 is:

16. The highest electrical conductivity of the following aqueous solutions is of?

17. Fused NaCl on electrolysis gives ………….. on cathode.

18. How many coulombs are required for the oxidation of 1 mole of H2O to O2?

19.  Molar conductivity of 0.15 M solution of KCl at 298 K, if its conductivity of 0.0152 S cm-¹ will be:

20. When heating one end of a metal plate, the other end gets hot because of: