Bases can dissociate in water to release ions other than
hydroxide. For example, sodamide (NaNH2) releases sodium cations
and anionic amide ions (NH2-). Only salts containing hydroxide
dissociate to release hydroxide ions (i.e. NaOH).
However, the released ion can then react with water to form
hydroxide ions. In the case of sodamide, the amide ion reacts with
water to produce ammonia and hydroxide ions. Note that the
hydroxide is not formed directly by dissociation of the salt, but
in a subsequent acid-base reaction.