Chemistry - Halogen Derivative Question with Solution | TestHub

Anions are more nucleophilic than neutral. So,${\mathrm{H}}_2\mathrm{O}$is least nucleophilic.
nucleophilicity$\propto {\mathrm{e}}^{-}\mathrm{ }$density



Greater the delocalization of charge, lesser will be nucleophilicity.

$\mathrm{O}{\mathrm{H}}^{-}>\mathrm{C}{\mathrm{H}}_3\mathrm{C}\mathrm{O}{\mathrm{O}}^{-}>\mathrm{C}{\mathrm{H}}_3\mathrm{S}{\mathrm{O}}_3^{-}>{\mathrm{H}}_2\mathrm{O}$