Question

The molar ionic conductivities of \[\ce{Mg^2+}\] and \[\ce{SO^2-_4}\] are 106.0 S cm² mol⁻¹ and 160.0 S cm² mol⁻¹ respectively. The value of limiting molar conductivity of \[\ce{MgSO}\], will be ______.

Options

• 266 S cm² mol⁻¹

• 622 S cm² mol⁻¹

• 288 S cm² mol⁻¹

• 822 S cm² mol⁻¹

Answer 1

The molar ionic conductivities of \[\ce{Mg^2+}\] and \[\ce{SO^2-_4}\] are 106.0 S cm² mol⁻¹ and 160.0 S cm² mol⁻¹ respectively. The value of limiting molar conductivity of \[\ce{MgSO}\], will be 266 S cm² mol⁻¹.

Explanation:

For a binary electrolyte like \[\ce{MgSO}\], the formula is:

`lambda_m^0 = lambda_+^0 + lambda_-^0`

`lambda_m^0 = lambda_{Mg^{2+}}^0 + lambda_{SO_4^{2-}}^0`

`lambda_m^0 = 106.0  S cm^-1 mol^-1 + 160.0  S cm^-1 mol^-1`

= 266.0 S cm⁻¹ mol⁻¹