Question

$S{O}_2$ and $C{l}_2$ both are used as bleaching agent. Factors that cause bleaching are respectively :

• A. $H$ (that causes reduction) , $O$ (that causes oxidation)
• B. $O$ (that causes reduction) , $H$ (that causes oxidation)
• C. $H$ (that causes oxidation) , $O$ (that causes reduction)
• D. $O$ (that causes oxidation) , $H$ (that causes reduction)

Answer 1

The correct option is A $H$ (that causes reduction) , $O$ (that causes oxidation)

Both sulphur dioxide and chlorine are good bleaching agents. Bleaching action of chlorine is based on oxidation while that of sulphur is based on reducing agent. Chlorine acts with water to produce nascent oxygen.

$S{O}_2+2H_{2}O\to H_{2}S{O}_4+H_2$

$2C{l}_2+2H_{2}O\to 4HCl+O_2$

This oxygen combines with coloured substance and makes it colourless.

Hence, in $S{O}_2$, $H$ causes reduction and in $C{l}_2$, $O$ causes oxidation.