WAEC Chemistry 2017 Paper

$\mathrm{Cu}^{2+} + 2\mathrm{e}^{-} \to \mathrm{Cu}_{(s)}$

$2 \times 96500\,\text{C} = 193000\,\text{C} \text{ deposits } 64\,\text{g} \text{ of } \mathrm{Cu}$

$M \propto I t$

$Q = I t = 0.45\,\text{A} \times 1\,\text{hr}\,15\,\text{min}$

= $0.45 \times 75 \times 60$ [converting the time to seconds]

Quantity of electricity passed = 2025C

$193000\,\text{C} \to 64\,\text{g}\,\mathrm{Cu}$

$1\,\text{C} \to \;\frac{64}{193000}$

$2025\,\text{C} \to \;\frac{64}{193000} \times 2025$

$= 0.6715\,\text{g} \approx\mathrm{eq} 0.67\,\text{g}$