Although geometries of NH _{3} and H _{2} O molecules are distorted tetrahedral, bond angle in water is less than that of Ammonia. Discuss.
Although geometries of NH _{3} and H _{2} O molecules are distorted tetrahedral, bond angle in water is less than that of Ammonia. Discuss.

Solution:

Ammonia’s central atom (N) has one lone pair and three bond pairs.

In water, the central atom (O) has two lone pairs and two bond pairs.

As a result, the two bond pairs repel the two lone pairs on the O- atom in the water molecule. And the attraction between the lone pair and the bond pair on the O-atom of H2O is stronger than the attraction between the lone pair and the bond pair on the N-atom of NH3.

As a result, despite their distorted tetrahedral structure, H2O has a lower bond angle than NH3.