The mass of \(Al\) produced during electrolysis is \(1.56 g\), what will be the mass of \(Cu\) deposited if the same quantity of electricity is used? \(Cu 63.5 Al -27\).
A. \(11.84 g\) B. \(238 g\) C. \(23.6 g\) D. \(5.3 g\)
Correct Answer: D
Explanation
\begin{aligned} &n_{A t}=\frac{1.56 g }{27 gmol ^{-1}}=0.05778 mol \\ &n_{C u}=x . \end{aligned}harge on aluminium, \(C_{A l}=3\)harge on copper \(= C _{ Cu }=2\)rom Faraday's second law of electrolysis, \(n_{A l} C_{A l}=n_{ Cu }\) \(C_{ C v}\) \(0.05778 \times 3=x \times 2\) \begin{aligned} x &=\left(\frac{0.05778 \times 3}{2}\right) mol \\ &=0.08667 mol \end{aligned} Mass of copper produced \(=\) mole of copper \(x\) molar mass \(=(0.08667 \times 63.5) g =5.5 g\)