# The density of Cu is $8.94gcm^{-3}$.The quantity of electricity needed to plate an area 10 cm $\times$ 10 cm to a thickness of $10^{-2}$cm using $CuSO_4$ solution is

$\begin{array}{1 1}13586C\\27172C\\40758C\\20348C\end{array}$

Amount of Cu deposited =mass of Cu deposited/molar mass of Cu
$\Rightarrow$(density $\times$ volume) of Cu deposited/molar mass of Cu
$\Rightarrow ( 8.94gcm^{-3})(10\times 10\times 10^{-2}cm^3)/(63gmol^{-1})=0.142$ mol
Since 2 electrons are required to convert $Cu^{2+}$ to Cu,the quantity of electricity needed is
$(2\times 96500Cmol^{-1})(0.142$ mol)=27388C