Question

What will be the concentration of NaCl solution, if the molar conductivity and conductivity of NaCl solution is 124.3 Ω⁻¹ cm² mol⁻¹ and 1.243 × 10⁻⁴ Ω⁻¹ cm² respectively?

Options

• 0.1 mol L⁻¹

• 0.001 mol L⁻¹

• 0.01 mol L⁻¹

• 0.02 mol L⁻¹

Answer 1

0.001 mol L⁻¹

Explanation:

Given,

Molar conductivity (λ_m) = 124.3 Ω⁻¹ cm² mol⁻¹

Conductivity (κ) = 1.243 × 10⁻⁴ Ω⁻¹ cm²

We know that,

Molar conductivity (λ_m) = `(κ xx 1000)/"M"`

M = `(κ xx 1000)/(λ_"m")`

= `(1.243 xx 10^-4 xx 1000)/(124.3)`

= 0.001 mol L⁻¹