Question

Account for the following :

BiH₃ is the strongest reducing agent amongst all the hydrides of group 15.

Answer 1

On moving down a group, the atomic size of elements increases. Thus, the stability of their hydrides decreases due to increase in the E–H bond length. BiH₃ has the least stability among group 15 halides. Thus, it is the strongest reducing agent among all the hydrides of group 15.