Question

Ammonia is a base but doesn't contain a hydroxyl group.

Answer 1

According to Lewis Theory a base is one that donates an electron pair .It is readily donates the electron pair, then it is strong base, otherwise weak base .NH3 has a lone pair of electrons on the Nitrogen atom and can donate this electron pair . Hence ammonia is consider as a base .Normally, it is accepted that a strong acid give rise to a weak conjugate base and weak base give rise to strong conjugate acid. when ammonia is dissolved in water it forms ammonium hydroxide. Ammonium hydroxide has the tendency to lose hydroxyl ion and hence act as a base.