How does chlorine gas give Cl^(-)Cl and ClO_3^(-)ClO3 upon basic hydrolysis?

1 Answer
Oct 18, 2016

This is a disproportionation reaction.

Cl_2(g) + +2HO^(-) rarr Cl^(-)+ClO^(-) +H_2OCl2(g)++2HOCl+ClO+H2O

Chlorine is simultaneously reduced and oxidized.

Explanation:

Cl_2(g) + 2HO^(-) rarr Cl^(-) + ClO^(-) + H_2OCl2(g)+2HOCl+ClO+H2O

Chlorine gas is OXIDIZED to hypochlorite (Cl,+I)(Cl,+I), and REDUCED to chloride ion, (Cl^-,-I)(Cl,I),.

"OXIDATION:"OXIDATION: 1/2Cl_2(g) + H_2O rarr ClO^(-) +2H^(+) + e^(-)12Cl2(g)+H2OClO+2H++e

"REDUCTION:"REDUCTION: 1/2Cl_2(g) + e^(-) rarr Cl^(-)12Cl2(g)+eCl

"OVERALL:"OVERALL: Cl_2(g) + H_2O rarr Cl^(-)+ClO^(-) +2H^(+) Cl2(g)+H2OCl+ClO+2H+

But we note that basic conditions were specified. How do we cope? We simply add 2xxHO^-2×HO to both sides.

Cl_2(g) + +2HO^(-) + cancel(H_2O) rarr Cl^(-)+ClO^(-) +cancel(2)H_2O

Here we have used the equation: H^+ + HO^(-) rarr H_2O, and cancelled out the waters.