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.

Options

1. ACl ₂(g)+ SO ₂(g)+2 H ₂ O (l) 2 HCl (a q)+ H ₂ SO ₄(a q)
2. BCl ₂(g)+2 SO ₂(g)+2 H ₂ O (l) 2 HCl (a q)+ H ₂ SO ₄(a q)
3. CCl ₂(g)+ SO ₂(g)+2 H ₂ O (l) 2 HCl (a q)+ H ₂ SO ₃(a q)
4. DCl ₂(g)+2 SO ₂(g)+2 H ₂ O (l) 2 HCl (a q)+ H ₂ SO ₃(a q)