Chlorine is used to 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.
The given redox reaction can be represented as follows:-
The oxidation half reaction is:-
The oxidation number is balanced by adding two electrons as:-
The charge is balanced by adding 4H+ ions as:-
The O atoms and H+ ions are balanced by adding 2H2O molecules as:-
The reduction half reaction is:-
The chlorine atoms are balanced as:-
The oxidation number is balanced by adding electrons as:-
The balanced chemical equation can be obtained by adding oxidation and reduction half equations to get the desired equation as: -
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