The dissociation of acid and base is a reversible process: ,
`HA hArr H^(+) +A^(-) BOH hArr B^(+) +OH^(-)`
Water helps in the dissociation of acids and bases (accelerates the forward process) in the following manner:
(i) With dilution the speed of the reverse process i.e., the combination of the ions to form undissociated acid or base decreases.
(ii) Water molecules form a sort of envelope around each ion of the acid or base. This acts as a protective cover and prevents the hydrated ions thus formed combining with each other to promote the reverse process.
