Question

Find the charge required to flow through an electrolyte to liberate one atom of (a) a monovalent material and (b) a divalent material.

Answer 1

(a) Amount of charge required by 1 equivalent mass of the substance = 96500 C
For a monovalent material,
equivalent mass = molecular mass
⇒ Amount of charge required by 6.023 × 10²³ atoms = 96500 C
∴ Amount of charge required by 1 atom = $\frac{96500}{6.023\times {10}^{23}}=1.6\times {10}^{-19}\mathrm{C}$

(b) For a divalent material,
equivalent mass =$\frac{1}{2}$molecular mass
⇒ Amount of charge required by $\frac{1}{2}$ × 6.023 × 10²³ = 96500 C
∴ Amount of charge required by 1 atom = 1.6 × 2 × 10⁻¹⁹ = 3.2 × 10⁻¹⁹ C