pBlock ElementsII - Result Question 72

True/False

67. The $H-N-H$ bond angle in $NH _3$ is greater than the $H-As-H$ bond angle in $AsH _3$.

(1984, 1M)

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Answer:

Correct Answer: 67. (True)

Solution:

Both ’ $N$ ’ and ‘$As$’ in corresponding hydrides are $s p^{3}$-hybridised. If central atoms are from same group, bond angle decreases from top to bottom if all other things are similar. Hence, $H-N-H$ bond angle in $NH _3$ is greater than $H-As-H$ bond angle in $AsH _3$.