Chlorine is used purify drinking water . Excess of chlorine is harmful . The excess of chlorine is removed by treating with sulphur dioxide . Present a balanced equation for this redox change taking place in water .

Chlorine is used purify drinking water . Excess of chlorine is harmful

1.	Chlorine is used purify drinking water . Excess of chlorine is harmful . The excess of chlorine is removed by treating with sulphur dioxide . Present a balanced equation for this redox change taking place in water .
Answer» Solution :The SKELETAL equation is : `Cl_2(g) +SO_2(AQ) + H_2O(l) rarr Cl^(-) (aq) +SO_4^(2-) (aq)` Reduction half equation : `Cl_2(aq) rarr Cl^(-) (aq)` Balancing Cl ATOMS `Cl_2(aq) rarr 2Cl^(-) (aq)` Balancing O. N. by adding electrons : `overset0(Cl_2)(aq)+2e^(-)rarr2Cl^(-)(aq) ""...(i)` Oxidation half equation : `SO_2(aq) rarr SO_4^(2-)(aq)` Balancing O.N. by adding electrons `OVERSET(+4)(SO_2)(aq) rarr overset(+6"")(SO_4^(2-))(aq)+2e^(-)` Balancing CHARGE adding `H^+` ions `SO_2(aq) rarr SO_4^(2-) (aq) +2e^(-) +4H^(+)(aq)` Balancing O atoms by adding `H_2O` `SO_2(aq) +2H_2O(l) rarr SO_4^(2-) (aq) +2e^(-) +4H^(+) (aq) ""...(ii)` Adding equations (i) and (ii) we gat `Cl_2(aq) + SO_2(aq) +2H_2O(l) rarr 2Cl^(-)(aq) +SO_4^(2-) (aq) +4H^(+) (aq)`