Question

Why is BiH3 the strongest reducing agent amongst all the hydrides of group 15 elements?

Answer 1

As we move down the group atomic size increases with decrease in the stability of the hydrides of group 15 elements occurs. As the stability of the hydrides of group 15 elements decreases, from NH3 to BiH3 the reducing character of hydrides from NH3 to BiH3 increases.

Answer 2

Hey !!

This is because BiH₃ is the least stable among the hydrides of Group 15.

Hope it helps you !!