What happens during electrolysis of znso4?

Answer 1

It depends on the electrodes being used :

1) If Pt(inert) electrodes are used, then the products will be:

Cathode: Zn2+ + 2e- ------> Zn

Anode: 2H20 ---------> 4H+ + O2 + 4e-

(or) 4OH- ----------> O2 + 4H2O + 4e-

(they are one and the same rxn )

SO42- is a spectator ion here.

Net rxn: 2Zn2+ + 2H2O ----------------> 2Zn + O2 + 4H+

(or) 2ZnSO4 + 2H2O -----------------> 2Zn + O2 + 2H2SO4

(use Pt electrode)

Also if not mentioned, always inert electrodes i.e. Pt electrodes are taken.

2) If very pure Zn electrodes are used, that too in an O2 free atmosphere, then the products will remain the same.

3) If some Cu impurity is present in the Zn electrode, then at cathode H2O (or H+) is reduced instead of Zn .

i.e. 2H+ + 2e- -----------> H2

or) 2H2O + 2e- ---------> H2 + 2OH-

Anode rxn remains the same.

4) If s pure Zn electrodeare used in an O2 atmosphere, then again H2O (or H+) is reduced instead of Zn. (the rxns are similar to case 3)

Answer 2

During electrolysis of ZnSO4, zinc ions (Zn2+) are reduced at the cathode to form solid zinc metal, while sulfate ions (SO4 2-) are oxidized at the anode to form oxygen gas and liquid water. This process allows for the separation of zinc from the electrolyte solution.