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.
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.

Solution:

The redox response is as given beneath:

${\mathrm{Cl}}_{2\left(s\right)}+{\mathrm{SO}}_{2\left(aq\right)}+{\mathrm{H}}_{2}{\mathrm{O}}_{\left(l\right)}\to {\mathrm{Cl}}_{\left(aq\right)}^{–}+S{O}_{4\left(aq\right)}^{2–}$

The oxidation half response:

$S{O}_{2}\left(aq\right)\to S{O}_{4\left(aq\right)}^{2–}$

$S{O}_{2\left(aq\right)}\to S{O}_{4\left(aq\right)}^{2–}+2{e}^{–}$

Add ions to surplus the charge:

$S{O}_{2\left(aq\right)}\to S{O}_{4\left(aq\right)}^{2–}+4{H}_{\left(aq\right)}^{+}+2{e}^{–}$

Add to surplus 0 particles and ions:

The decrease half response:

Equilibrium Cl iotas: