a. Would you except the hydrides of `N,O` and `F` to have lower boiling points than the hydrides of their subsequent group members? Give reason.
b. Can phosphorous with outer electronic configuration `3s^(2)3p^(3)` form `PH_(5)`?
c. How many hydrogen-bonded water molecules(s) are associated with `CuSO_(4).5H_(2)O`?

Explanation

On the basis of molecular masses of `NH_(3).H_(2)O and HF`, their boiling points are expected to be lower than those of the subsequent group member hydrides. However, due to higher electronegativity of N,O and F, the magnitude of hydrogen bonding in their hydrides will be quite appreaciable. Hence, the boiling points of `NH_(3),H_(2)O and HF` will be higher than the hydrides of their subsequent group members.