Question

When a certain conductivity cell was filled with 0·05 M KCl solution, it has a resistance of 100 ohm at 25ºC. When the same cell was filled with 0·02 M AgNO₃ solution, the resistance was 90 ohm. Calculate the conductivity and molar conductivity of AgNO₃ solution. (Given : Conductivity of 0·05 M KCl solution = 1·35 × 10⁻² ohm⁻¹cm⁻¹)

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?