Question

The quantity of electricity required to produce 9.6 g of Mg by electrolysis of MgCl₂ is ____________.

[Given: Atomic mass of Mg = 24 g mol⁻¹]

Options

• 0.4 F

• 0.8 F

• 2.5 F

• 4.8 F

Answer 1

The quantity of electricity required to produce 9.6 g of Mg by electrolysis of MgCl₂ is 0.8 F.

Explanation:

Moles of Mg produced = `"Mass of Mg produced"/"Atomic mass of Mg"`

= `9.6/24`

= 0.4 mol

The half-reaction for the reduction of Mg²⁺ is:

\[\ce{Mg^2+ + 2e^- -> Mg}\]

Therefore, one mole of Mg is produced by the passage of 2 Faradays.

∴ Number of Faradays of electricity required to produce 0.4 mol of Mg = 0.4 × 2 = 0.8 F