Chemical Bonding and Molecular Structure - Result Question 40
####41. Consider the molecules $CH_4, NH_3$ and $H_2 O$. Which of the given statements is false? [2016]
(a) The $H-C-H$ bond angle in $CH_4$, the $H-N-H$ bond angle in $NH_3$, and the $H-O-H$ bond angle in $H_2 O$ are all greater than $90^{\circ}$
(b) The $H-O-H$ bond angle in $H_2 O$ is larger than the $H-C-H$ bond angle in $CH_4$.
(c) The $H-O-H$ bond angle in $H_2 O$ is smaller than the $H-N-H$ bond angle in $NH_3$.
(d) The $H-C-H$ bond angle in $CH_4$ is larger than the $H-N-H$ bond angle in $NH_3$.
Show Answer
Solution:
- (b)
The geometry of $H_2 O$ should have been tetrahedral if there are all bond pairs. But due to presence of two lone pairs the shape is distorted tetrahedral. Hence bond angle reduced to $104.5^{\circ}$ from $109.5^{\circ}$.
