Compare the bleaching action of `Cl_(2)` and `SO_(2)`.

Explanation

`to Cl_(2)` is a powerful bleaching agent. This bleaching action is due to oxidation.
`Cl_(2)+H_(2)O to2HCl+(O)`
Coloured substance + (O) `to` colourless substance.
`to` It bleaches vegetable or organic matter in the presence of moisture. Bleaching effect of `Cl_(2)` is permanent.
`to SO_(2)` acts as bleaching agent in presence of moisture.
`SO_(2)+2" H"_(2)O to H_(2)SO_(4)+2[H]`
Colouring matter `+2[H]to` colourless product
Nascent
hydrogen.
`to SO_(2)` bleaches wool and silk.