In the electrolysis of $CuCl_2$ solution using copper electrode,if 2.5g of Cu is deposited at cathode,then at anode

Question

$\begin{array}{1 1}\text{890 mL of }Cl_2\text{ at STP is deposited}\\\text{445 mL of }O_2\text{ at STP is liberated}\\\text{2.5g of copper is deposited}\\\text{a decrease of 2.5g of mass takes place}\end{array}$