Question

Resistance of conductivity cell filled with 0.1 M KCl solution is 100 ohms. If the resistance of the same cell when filled with 0.02 M KCl solution is 520 ohms, calculate the conductivity and molar conductivity of 0.02 M KCl solution. 

[Given : Conductivity of 0.1 M KCl solution is 1.29 Sm^-1.]

Answer 1

Given : 

Resistance of 0.1 M KCl solution = R₁ = 100 Ω

Resistance of 0.02 M KCl solution = R₂ = 520 Ω

Conductivity of 0.02 M KCl solution = κ₂ = ?

Molar conductivity of 0.02 M KCl solution = ∧_m = ?

Conductivity of 0.1 M KCl solution = κ₁

= 1.29 S m^-1

Cell constant = b = κ₁ × R₁ = 1.29 × 100

= 129 m^-1

= 1.29 cm^-1