Electrochemistry Most Important MCQ’s for Board Exams | Class 12 Chemistry

In This Post we Are Discussing About Electrochemistry Class 12 Chemistry Most Important MCQ’s for Board Exams 2025, As we all know, MCQs play a crucial role at the beginning of the Class 12 Board Exam paper. A strong start with the right MCQs can set a positive tone for the entire exam and pave the way for achieving the best possible score. In this post, we’re sharing the most important MCQs for Chemistry Electrochemistry Chapter that will help you kick off your exam with confidence and success!

Electrochemistry is a crucial chapter in Class 12 Chemistry, frequently appearing in board exams. Mastering this chapter can help students score high marks, as it involves fundamental concepts like electrochemical cells, Nernst equation, and conductivity. To help students prepare effectively, we have compiled the most important multiple-choice questions (MCQs) based on previous years’ board exam patterns.

So Read Whole Article and in The Bottom You Will Get Solutions Most Important MCQ’s for Class 12 Board Exams 2025 PDF Link too.

Electrochemistry Most Important MCQ’s

1. Consider the following standard electrode potential values:
Fe³⁺ + 1e⁻ → Fe²⁺; E° = +0.77 V
MnO₄⁻ + 8H⁺ + 5e⁻ → Mn²⁺ + 4H₂O; E° = +1.51 V
What is the cell potential for the redox reaction?
(a) +2.28 V
(b) -0.74 V
(c) -2.28 V
(d) +0.74 V

2. The standard electrode potential for Sn⁴⁺/Sn²⁺ couple is +0.15 V and for Cr³⁺/Cr couple is -0.73 V. These two couples are connected to make an electrochemical cell. The redox reaction is spontaneous. The cell potential will be:
(a) +0.88 V
(b) +0.58 V
(c) -0.88 V
(d) -0.58 V

3. The standard electrode potential for Ni²⁺/Ni couple is -0.25 V and for Ag⁺/Ag couple is 0.80 V. These two couples are connected to make an electrochemical cell. The redox reaction is spontaneous. The cell potential will be:
(a) +1.05 V
(b) -1.05 V
(c) +0.55 V
(d) -0.55 V

4. The correct cell to represent the following reaction is:
Zn + 2Ag⁺ → Zn²⁺ + 2Ag
(a) 2Ag | Ag⁺ || Zn | Zn²⁺
(b) Ag⁺ | Ag || Zn²⁺ | Zn
(c) Ag | Ag⁺ || Zn | Zn²⁺
(d) Zn | Zn²⁺ || Ag⁺ | Ag

5. ΔG and E° cell for a spontaneous reaction will be:
(a) positive, negative
(b) negative, negative
(c) negative, positive
(d) positive, positive

6. Ag⁺ (aq) + e⁻ → Ag (s), E° = +0.80 V
Fe²⁺ (aq) + 2e⁻ → Fe (s), E° = 0.44 V
Find the E° cell for:
Fe (s) + 2Ag⁺ (aq) → Fe²⁺ (aq) + 2Ag (s)
(a) 1.6 V
(b) -1.16 V
(c) 2.04 V
(d) 1.24 V

7. A voltaic cell is made by connecting two half cells represented by half-equations below:
Sn²⁺ (aq) + 2e⁻ → Sn (s) E° = -0.14 V
Fe³⁺ (aq) + e⁻ → Fe²⁺ (aq) E° = +0.77 V
Which statement is correct about this voltaic cell?
(a) Fe²⁺ is oxidized and the voltage of the cell is -0.91 V
(b) Sn is oxidized and the voltage of the cell is 0.91 V
(c) Fe²⁺ is oxidized and the voltage of the cell is 0.91 V
(d) Sn is oxidized and the voltage of the cell is 0.63 V

8. Four half reactions I to IV are shown below:
I. 2Cl⁻ → Cl₂ + 2e⁻
II. 4OH⁻ → O₂ + 2H₂O + 2e⁻
III. Na⁺ + e⁻ → Na
IV. 2H⁺ + 2e⁻ → H₂
Which two of these reactions are most likely to occur when concentrated brine is electrolyzed?
(a) I and III
(b) I and IV
(c) II and III
(d) II and IV

9. Consider the following standard electrode potential values:
Sn²⁺ (aq) + 2e⁻ → Sn(s) E° = -0.14 V
Fe³⁺ (aq) + e⁻ → Fe²⁺ (aq) E° = +0.77 V
What is the cell reaction and potential for the spontaneous reaction that occurs?
(a) 2Fe²⁺ (aq) + Sn²⁺ (aq) → 2Fe³⁺ (aq) + Sn(s) E° = -0.91 V
(b) 2Fe³⁺ (aq) + Sn(s) → 2Fe²⁺ (aq) + Sn²⁺ (aq) E° = +0.91 V
(c) 2Fe²⁺ (aq) + Sn²⁺ (aq) → 2Fe³⁺ (aq) + Sn(s) E° = +0.91 V
(d) 2Fe³⁺ (aq) + Sn(s) → 2Fe²⁺ (aq) + Sn²⁺ (aq) E° = +1.68 V

10. An electrochemical cell behaves like an electrolytic cell when
(a) E_cell = E_external
(b) E_cell = 0
(c) E_external > E_cell
(d) E_external < E_cell

11. Which of the following solutions of KCl will have the highest value of molar conductivity?
(a) 0.01 M
(b) 1 M
(c) 0.5 M
(d) 0.1 M

12. Kohlrausch gave the following relation for strong electrolyte:
Λ = Λ₀ – A√C
Which of the following equality holds true?
(a) Λ = Λ₀ as C → √A
(b) Λ = Λ₀ as C → 0
(c) Λ = Λ₀ as C → ∞
(d) Λ = Λ₀ as C → 1

13. The unit of molar conductivity is
(a) S cm⁻² mol⁻¹
(b) S cm² mol⁻¹
(c) S⁻¹ cm² mol⁻¹
(d) S cm² mol

14. Which of the following cells was used in the Apollo space program?
(a) Dry cell
(b) Ni-Cd cell
(c) H₂-O₂ fuel cell
(d) Mercury cell

15. In a lead storage battery
(a) PbO₂ is reduced to PbSO₄ at the cathode.
(b) Pb is oxidized to PbSO₄ at the anode.
(c) Both electrodes are immersed in the same aqueous solution of H₂SO₄.
(d) All the above are true.

16. The number of Faradays passed through a solution of CuSO₄ to produce 1 mol of Cu and O₂ will be:
(a) 1.0
(b) 4.0
(c) 8.0
(d) 2.0