The decreasing order of boiling points of the following hydrides is

Options

A. `SbH_(3) gt AsH_(3) gt PH_(3) gt NH_(3)`
B. `NH_(3) gt SbH_(3) gt AsH_(3) gt PH_(3)`
C. `SbH_(3) gt NH_(3) gt AsH_(3) gt PH_(3)`
D. `PH_(3) gt AsH_(3) gt SbH_(3) gt NH_(3)`

Answer

C

Explanation

`NH_(3)` has abnormally high boiling points because of their tendency to form hydrogen bonds. `NH_(3)` has higher boiling point than phosphine and then boiling point increases down the group because of increase in size. Hence, the order of boiling point will be `SbH_(3) gt NH_(3) gt AsH_(3) gt PH_(3)`