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

1 Answer
Oct 18, 2016

Answer:

This is a disproportionation reaction.

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

Chlorine is simultaneously reduced and oxidized.

Explanation:

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

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

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

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

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

But we note that basic conditions were specified. How do we cope? We simply add #2xxHO^-# 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.