Explain bleaching action of chlorine. Or Cl_(2) acts as a bleaching agent. Or Bleaching of flowers by chlorine is permanent while that by sulphur dioxideis temporary. Explain.

Explain bleaching action of chlorine. Or Cl_(2) acts as a bleaching a

1.	Explain bleaching action of chlorine. Or Cl_(2) acts as a bleaching agent. Or Bleaching of flowers by chlorine is permanent while that by sulphur dioxideis temporary. Explain.
Answer» SOLUTION :In presence of moisture or in aqueous solution, `Cl_(2)` releases nascent oxygen which oxidises organic colouring material to colourless material. Thus, bleaching by `Cl_(2)` is by oxidation and hence permanent. `{:(""Cl_(2) + H_(2)O rarr 2 HCl + [O] ("nascent oxygen")),("Coloured material" + [O] rarr "Colourless material"):}` In contrast, in presence of moisture, `SO_(2)` liberates nascent hydrogen which REDUCES coloured material to colourless material. Thus, bleaching by `SO_(2)` is by reduction and hence temporary. `{:(""SO_(2)+2H_(2)O rarr H_(2)SO_(4) + 2 [H] ("nascent hydrogen")),("Colourless substance" + [H] rarr "Colourless material"):}`