Question

Among the hydrides of group 15, predict the hydride having least basic character.

Answer 1

1. Among group 15 hydrides (NH₃, PH₃, AsH₃, SbH₃, BiH₃), basicity decreases down the group.
2. Basic character depends on the lone pair donation ability of the central atom.
3. Nitrogen’s small size causes higher electron density on its lone pair, making NH₃ the strongest base.
4. As atom size increases from N to Bi, electron density on the lone pair decreases, lowering basicity.
5. BiH₃ has the least basic character among group 15 hydrides.

Thus, BiH₃ is the hydride with least basic character in group 15 elements.