Question

Ammonia is a base.
But why don't it has a hydroxyl group in it?​

Answer 1

Ammonia instead of not having hydroxyl group is a base because it forms OH- ions when added to water as it ionises to form ammonium ions and hydroxide ions after forming ammonium hydroxide when mixed in water. Ammonia is a base but doesn't contain any hydroxyl group because it forms OH- ions when it is added to water.

Answer 2

Ammonia is a base based on the bronsted-lowry concept because it is capable of accepting H+ and becoming NH4+

It can also be said to be a base based on Lewis concept since nitrogen atom posses lone pair

So bases aren't classified based on whether they have hydroxyl group or not

In most cases, we classify compounds as acid or base based on Lewis concept

HOPE IT HELPS!!