Question
In the electrolysis of $$CuC{l_2}$$ solution, the mass of the cathode increased by $$3.2\,g.$$ What occured at the copper anode?
A.
$$0.12$$ litre of $$C{l_2}$$ was liberated
B.
0.56 litre of $${O_2}$$ was liberated
C.
$$0.1\,mol\,C{u^{2 + }}$$ passed into the solution.
D.
$$0.05\,mol$$ $$C{u^{2 + }}$$ passed into the solution.
Answer :
$$0.05\,mol$$ $$C{u^{2 + }}$$ passed into the solution.
Solution :
The amount. of copper deposited at cathode by reduction of $$C{u^{2 + }}\,ions$$ is $$\frac{{3.2}}{{63}} = 0.05\,moles.$$
The same amount $$0.05\,mole$$ of $$C{u^{2 + }}$$ must pass into solution from anode by oxidation.