Question

Resistance of a conductivity cell filled with 0.2 mol L⁻¹ KCl solution is 200 Ω. If the resistance of the same cell when filled with 0.05 mol L⁻¹ KCl solution is 620 Ω, calculate the conductivity and molar conductivity of 0.05 mol L⁻¹ KCl solution. The conductivity of 0.2 mol L⁻¹ KCl solution is 0.0248 S cm⁻¹.

Give reasons: (i) Mercury cell delivers a constant potential during its life time. (ii) In the experimental determination of electrolytic conductance, Direct Current (DC) is not used.

Define fuel cell with an example. What advantages do the fuel cells have over primary and secondary batteries?

Answer the following questions (Any two): (a) Why is alternating current used instead of direct current for measuring resistance of an electrolytic solution? (b) State Kohlrausch's law of independent migration of ions. (c) Depict the Galvanic cell in which the following reaction takes place: Mg (s) + Cu²⁺ (aq) → Mg²⁺ (aq) + Cu (s)