1.

Standard free energies of formation (in kJ/mol) at 298 K are −237.2, −394.4, and −8.2 for H₂O(l), CO₂(g), and pentane(l) respectively. The value of Ecell0E^0_{cell}Ecell0​ for the pentane–oxygen fuel cell is:
a) 1.0968 V
b) 0.0968 V
c) 1.968 V
d) 2.0968 V
Answer: a

2.

The potential of the following cell is 0.34 V at 25°C. Calculate the standard reduction potential of the copper half cell.
Pt | H₂ (1 atm) || Cu²⁺ (1 M) | Cu
a) 0.34 V
b) −0.34 V
c) 3.4 V
d) −3.4 V
Answer: a

3.

The standard reduction potential of Cu²⁺/Cu and Cu²⁺/Cu⁺ are 0.337 V and 0.153 V respectively. The standard electrode potential of Cu⁺/Cu half-cell is:
a) 0.184 V
b) 0.827 V
c) 0.521 V
d) 0.490 V
Answer: c

4.

For a cell reaction involving two-electron change, the standard EMF is 0.295 V at 25°C. The equilibrium constant will be:
a) 2.95 × 10⁵
b) 10
c) 1.0 × 10¹⁰
d) 2.95 × 10⁻¹⁰
Answer: c

5.

The relationship between Gibbs free energy change (ΔG) and emf (E) is:
a) ΔG = nFE
b) ΔG = −nFE
c) ΔG = nF/E
d) ΔG = E/nFE
Answer: b

6.

Given:
Zn → Zn²⁺ + 2e⁻, E° = −0.76 V
Fe → Fe²⁺ + 2e⁻, E° = −0.44 V
The EMF for: Zn + Fe²⁺ → Zn²⁺ + Fe is:
a) −0.32 V
b) 0.32 V
c) 1.20 V
d) −1.20 V
Answer: b

7.

The standard redox potentials (acidic medium) are:
Cr₂O₇²⁻/Cr³⁺ = 1.33 V, MnO₄⁻/Mn²⁺ = 1.51 V, Ce⁴⁺/Ce³⁺ = 1.61 V.
Oxidising power decreases in the order:
a) Cr₂O₇²⁻ > Ce⁴⁺ > MnO₄⁻
b) MnO₄⁻ > Ce⁴⁺ > Cr₂O₇²⁻
c) Ce⁴⁺ > MnO₄⁻ > Cr₂O₇²⁻
d) Cr₂O₇²⁻ > MnO₄⁻ > Ce⁴⁺
Answer: c

8.

The standard electrode potential of the hydrogen electrode is:
a) 1 V
b) 6 V
c) 8 V
d) 0 V
Answer: d

9.

Standard oxidation potentials (V):
Zn = +0.76, Cu = +0.34, Ag = −0.80, Ni = +0.25
Maximum voltage is obtained from:
a) Cu + 2Ag⁺ → Cu²⁺ + 2Ag
b) Zn + 2Ag⁺ → Zn²⁺ + 2Ag
c) Ni + 2H⁺ → Ni²⁺ + H₂
d) Zn + Cu²⁺ → Zn²⁺ + Cu
Answer: b

10.

If Ered0E^0_{red}Ered0​ values of A, B, C are +0.68 V, −2.54 V, −0.50 V, the reducing power order is:
a) A > B > C
b) B > C > A
c) C > B > A
d) B > C > A
Answer: d

11.

For reaction: Cu + 2Ag⁺ → Cu²⁺ + 2Ag, E° = 0.46 V.
The equilibrium constant at 298 K is:
a) 2.0 × 10⁸
b) 4.0 × 10⁸
c) 4.0 × 10¹⁵
d) 2.4 × 10⁸
Answer: c

12.

In an electrolytic cell, the cathode acts as a:
a) oxidising agent
b) reducing agent
c) both
d) none
Answer: b

13.

Which reaction is spontaneous?
a) Zn²⁺ + Cu → Zn + Cu²⁺
b) Cu²⁺ + Zn → Cu + Zn²⁺
c) Zn²⁺ + Cu²⁺ → Zn + Cu
d) none
Answer: b

14.

For reaction:
Zn + Cu²⁺ (0.1 M) → Zn²⁺ (1 M) + Cu,
E° = 1.10 V. Cell potential is:
a) 2.14 V
b) 1.80 V
c) 0.82 V
d) 1.07 V
Answer: d

15.

A current of 3.86 A is passed for 50 min and 2.4 g of a divalent metal is deposited. Atomic weight is:
a) 24
b) 28
c) 64
d) 40
Answer: d

16.

Calculate emf of: Cu | Cu²⁺ || Ag⁺ | Ag
a) −1.14 V
b) 1.14 V
c) −0.46 V
d) 0.46 V
Answer: d

17.

If K < 1, ΔG° will be:
a) 1
b) zero
c) negative
d) positive
Answer: d

18.

For Zn | Zn²⁺ || Cu²⁺ | Cu with E° = 1.10 V, maximum work is:
a) −318.45 kJ
b) −212.30 kJ
c) −424.60 kJ
d) −106.15 kJ
Answer: b

19.

Electrode potential of Ni²⁺ (0.1 M) | Ni is:
a) −0.22 V
b) −0.28 V
c) −0.34 V
d) −0.82 V
Answer: b

20.

Which combination gives maximum EMF?
a) (i) and (ii)
b) (ii) and (iii)
c) (ii) and (iv)
d) (iii) and (iv)
Answer: b

21.

The metal that does not displace hydrogen from acid is:
a) Ca
b) Zn
c) Al
d) Hg
Answer: d

22.

Two cells Fe|Fe²⁺||Cu²⁺|Cu and Zn|Zn²⁺||Cu²⁺|Cu connected in series. Net emf is:
a) 1.10 V
b) 0.75 V
c) 0.35 V
d) 1.85 V
Answer: d

23.

Standard EMF for Fe + 2Fe³⁺ → 3Fe²⁺ is:
a) 1.111 V
b) 0.330 V
c) 1.653 V
d) 1.212 V
Answer: d

24.

Find emf of Zn | Zn²⁺ || Cu²⁺ | Cu:
a) 1.10 V
b) −1.10 V
c) −0.76 V
d) −0.42 V
Answer: a

25.

For reaction 2Fe³⁺ + 2I⁻ → 2Fe²⁺ + I₂, E°cell is:
a) 1.006 V
b) 0.503 V
c) 0.235 V
d) −0.235 V
Answer: c

26.

EMF of Mg/Mg²⁺ and Cu/Cu²⁺ cell is:
a) 2.30 V
b) 1.336 V
c) 2.71 V
d) 2.03 V
Answer: c

27.

For feasibility of redox reaction, emf must be:
a) positive
b) fixed
c) zero
d) negative
Answer: a

28.

Potential of Pt in 0.1 M Sn²⁺ and 0.01 M Sn⁴⁺ is:
a) E°
b) E° + 0.059
c) E° + 0.059/2
d) E° − 0.059/2
Answer: c

29.

Ag⁺/Ag = 0.80 V and Cu⁺/Cu = 0.34 V. Correct statement is:
a) Cu cathode, E° = 0.46 V
b) Ag anode, E° = −0.34 V
c) Cu anode, E° = +0.46 V
d) Ag cathode, E° = −0.34 V
Answer: c

30.

Kohlrausch’s law states that at:
a) Infinite dilution, each ion makes a definite contribution to conductance of an electrolyte depending on the nature of the other ion
b) Infinite dilution, each ion makes a definite contribution to equivalent conductance of an electrolyte, whatever be the nature of the other ion
c) Finite dilution, each ion makes a definite contribution to equivalent conductance of an electrolyte, whatever be the nature of the other ion
d) Infinite dilution, each ion makes a definite contribution to conductance of an electrolyte

Answer: b