AIPMT Mains Chemistry Electrochemistry Class 12 Questions

Standard reduction potentials of the half reactions are given below: F₂(g) + 2e⁻ → 2F⁻ (aq) ; E° = +2.85 V Cl₂(g) + 2e⁻ → 2Cl⁻ (aq) ; E° = +1.36 V Br₂(l) + 2e⁻ → 2Br⁻ (aq) ; E° = +1.06 V I₂(s) + 2e⁻ → 2I⁻ (aq) ; E° = +0.53 V The strongest oxidising and reducing agents respectively are:

Molar conductivities (Λ°) at infinite dilution of NaCl, HCl and CH₃COONa are 126.4, 425.9 and 91.0 S cm² mol⁻¹ respectively. Λ° for CH₃COOH will be:

Four successive members of the first series of the transition metals are listed below. For which one of them the standard potential (E°_{M²⁺/M}) value has a positive sign?

The Gibbs' energy for the decomposition of Al₂O₃ at 500°C is as follows:

$\frac{2}{3} \text{Al}_2\text{O}_3 \rightarrow \frac{4}{3} \text{Al} + \text{O}_2 ; \Delta G = +960 \text{kJ mol}^{-1}$

The potential difference needed for the electrolytic reduction of aluminium oxide (Al₂O₃) at 500°C is at least:

A solution contains Fe²⁺, Fe³⁺ and I⁻ ions. This solution was treated with iodine at 35°C. E° for Fe³⁺/Fe²⁺ is +0.77 V and E° for I₂/2I⁻ = 0.536 V. The favourable redox reaction is

Which of the following expressions correctly represents the equivalent conductance at infinite dilution of Al₂(SO₄)₃? Given that Λ₀Al³⁺ and Λ₀SO₄²⁻ are the equivalent conductances at infinite dilution of the respective ions?

Consider the following relations for emf of an electrochemical cell (a) emf of cell = (Oxidation potential of anode) – (Reduction potential of cathode) (b) emf of cell = (Oxidation potential of anode) + (Reduction potential of cathode) (c) emf of cell = (Reductional potential of anode) + (Reduction potential of cathode) (d) emf of cell = (Oxidation potential of anode) – (Oxidation potential of cathode)

Which of the above relations are correct?

Given:

(i) Cu²⁺ + 2e⁻ → Cu, E° = 0.337 V

(ii) Cu²⁺ + e⁻ → Cu⁺, E° = 0.153 V

Electrode potential, E° for the reaction, Cu⁺ + e⁻ → Cu, will be:

Al₂O₃ is reduced by electrolysis at low potentials and high currents. If 4.0 × 10⁴ amperes of current is passed through molten Al₂O₃ for 6 hours, what mass of aluminium is produced? (Assume 100% current efficiency. At. mass of Al = 27 g mol⁻¹ )

The equivalent conductance of M/32 solution of a weak monobasic acid is 8.0 mhos cm² and at infinite dilution is 400 mhos cm². The dissociation constant of this acid is:

Kohlrausch's law states that at

Standard free energies of formation (in kJ/mol) at 298 K ar$e^{-237}$.2, -394.4 an$d^{-8}$.2 for H₂O (l), CO₂ (g) and pentane (g) respectively. The value of E°cell for the pentane-oxygen fuel cell is

On the basis of the following E° values, the strongest oxidizing agent is [Fe(CN)₆]³⁻ → [Fe(CN)₆]⁴⁻ + e⁻; E° = -0.35 V Fe²⁺ → Fe³⁺ + e⁻; E° = -0.77 V