Question

On electrolyzing ${\mathrm{CuSO}}_4$, solution in presence of $\mathrm{Pt}$, the solution becomes colorless, why?

Answer 1

Electrolysis:

1. It is a process in which a electric current is passed to the aqueous or molten state of an element to induce a chemical reaction.
2. The positive terminal end is anode and the negative terminal end is called cathode.
3. Oxidation occurs at anode and reduction occurs at cathode.
4. Copper ions present in solution are discharged on Pt electrode during electrolysis and thus, blue color of solution (which was formed due to the presence of the copper ions initially) disappears( as Copper ions get converted into Copper metal).
5. The reaction can be given as,

At cathode :

${\mathrm{Cu}}^{2+}+2{\mathrm{e}}^{-}\to \mathrm{Cu}$

At anode:

$2{\mathrm{OH}}^{-}\to {\mathrm{H}}_2\mathrm{O}+0.5{\mathrm{O}}_2+2{\mathrm{e}}^{-}$