Question

Copper sulphate solution is electrolysed using copper electrodes. State one relevant observation.

Answer 1

• Electrolysis is a process in which a compound gets dissociates into ions in the aqueous or molten state.
• During the electrolysis of copper sulfate $\left({\mathrm{CuSO}}_4\right)$ solution using copper electrodes, the copper metal $\left(\mathrm{Cu}\right)$ deposits at the cathode give reddish-pink color.
• Chemical equation : $$\begin{gathered} {\mathrm{CuSO}}_4\left(\mathrm{aq}\right)\to {\mathrm{Cu}}^{2+}\left(\mathrm{aq}\right)+{\mathrm{SO}}_4^{2-}\left(\mathrm{aq}\right) \\ \mathrm{copper}\mathrm{sulphate}\mathrm{copper}\mathrm{ion}\mathrm{sulphate}\mathrm{ion} \end{gathered}$$
• At cathode: ${\mathrm{Cu}}^{2+}\left(\mathrm{aq}\right)+2{\mathrm{e}}^{-}\to \mathrm{Cu}\left(\mathrm{s}\right)$
• Hence, one can observe the deposition of Cu metal at the cathode (one of the electrodes).