The reaction $Cl_2 + 2OH^{-} \to ClO^{-} + Cl^{-} + H_2O$ represents the process of bleaching. Identify and name the species that bleaches the substances due to its oxidising action.

(N/A) In the given reaction,the oxidation number of $Cl$ changes from $0$ to $+1$ (in $ClO^{-}$) and from $0$ to $-1$ (in $Cl^{-}$).
This is a disproportionation reaction where $Cl_2$ acts as both an oxidising and a reducing agent.
The species $ClO^{-}$ (hypochlorite ion) is responsible for the bleaching action due to its strong oxidising nature.