Question

The decreasing order of the boiling points of the following hydrides
(i) `NH_3` (ii) `PH_3`
(iii) `AsH_3` (iv) `SbH_3`
(v) `H_2O` is
A. VgtIVgtIgtIIIgtII
B. VgtIgtIIgtIIIgtIV
C. IgtIVgtIIIgtIIgtV
D. IVgtIIIgtIgtIIgtV

Answer 1

Correct Answer - A
The b.pt of `SbH_(3)` is higher than that of `NH_(3)`. The reason being that the stronger van der walls forces of attraction more than compensate the rease in b.pt of `NH_(3)` due to H-bonding (A ) is correct.