Question

Molar conductivities at infinite dilution of Mg²⁺ and Br^- are 105.8 Ω^-1 cm2 mol^-1 and 78.2 Ω^-1 cm² mol^-1 respectively. Calculate molar conductivity at zero concentration of MgBr₂.

Answer 1

According to Kohlrausch law,

`Λ_0("MgBr"_2) = λ_("Mg"2+)^0 + 2λ_("Br"-)^0`

`Λ_0("MgBr"_2) = 105.8 + 2 xx 78.2 = 262.2 Ω^(-1) "cm"^2 "mol"^(-1)`