• # question_answer 12) Although geometries of $N{{H}_{3}}$ and ${{H}_{2}}O$molecules are distorted tetrahedral, bond angle in water is less than that of ammonia. Discuss.

In$N{{H}_{3}}$, there is one lone pair on N-atom which repels bond pairs whereas in ${{H}_{2}}O$, there are two lone pairs on O-atom which repel bond pairs. Thus, repulsion is more in${{H}_{2}}O$ than in $N{{H}_{3}}$ and hence, the bond angle in water is less than in$N{{H}_{3}}$.