Question
Although geometries of NH3 and H2O molecules are distorted tetrahedral, the bond angle in water is less than that of ammonia. Discuss.
Solution
In NH3, there are three bond pairs and one lone pair on N-atom. There is only one lone pair on N-atom to repel the bond pairs. In H2O, there are two bond pairs and two lone pairs on O-atom. There are two lone pairs on O-atom to repel the bond pairs. Hence, the repulsions on bond pairs are greater in H2O than in NH3 and hence the bond angle is less.
