Question

The ions responsible for the bleaching action of bleaching powder and the ions responsible for loss of bleaching action of bleaching powder due to the storage for long time respectively are:

• A. $C{l}^{-},OC{l}^{-}$
• B. $OC{l}^{-},C{l}^{-}$
• C. $OC{l}^{-},Cl{O}_3^{-}$
• D. $C{l}^{-},Cl{O}^{-}$

Answer 1

Answer: (C)

$OC{l}^{-},Cl{O}_3^{-}$

Bleaching powder contains $C{a}^{2+},C{l}^{-},OC{l}^{-}$ ions. Among these $OC{l}^{-}$ ions hydrolyse to give nascent oxygen. Hence these are responsible for the bleaching action.

On long standing $OC{l}^{-}$ ions get oxidized to $Cl{O}_3^{-}$ ions which result in loss of bleaching action of bleaching powder.