$BF_3$ is used as a catalyst in several industrial processes due to its

In which of the following covalent compounds is the bond angle maximum?

$S +$ Conc. $H_2SO_4 \longrightarrow X + Y$
Here $X$ is a gas and $Y$ is a liquid and both are triatomic molecules. The number of electron lone pairs present on the central atoms of $X$ and $Y$ are respectively.

The correct pair of species which are not isostructural is

Which of the following pairs of species have identical shapes?

In the $BrF_3$ molecule,the lone pairs are arranged at equatorial positions to minimize ........................