Q5 / 225 · JEE Main 2004 · Chemistry
The correct order of bond angles (smallest first) in $\mathrm{H}_2 \mathrm{~S}, \mathrm{NH}_3, \mathrm{BF}_3$ and $\mathrm{SiH}_4$ is
- A$\mathrm{H}_2 \mathrm{~S} < \mathrm{SiH}_4 < \mathrm{NH}_3 < \mathrm{BF}_3$
- B$\mathrm{H}_2 \mathrm{~S} < \mathrm{NH}_3 < \mathrm{BF}_3 < \mathrm{SiH}_4$
- Correct answerC$\mathrm{H}_2 \mathrm{~S} < \mathrm{NH}_3 < \mathrm{SiH}_4 < \mathrm{BF}_3$
- D$\mathrm{NH}_3 < \mathrm{H}_2 \mathrm{~S} < \mathrm{SiH}_4 < \mathrm{BF}_3$
Solution
$\mathrm{H}_2 \mathrm{~S} \longrightarrow \mathrm{sp}^3$
$\mathrm{NH}_3 \longrightarrow \mathrm{sp}^3$
$\mathrm{BF}_3 \longrightarrow \mathrm{sp}^2$
$\mathrm{SiH}_4 \longrightarrow \mathrm{sp}^3$
Hence, the correct answer is option: 'C'.