Question

Arrange this in the order of property indicated: NH₃, PH₃, AsH₃, SbH₃, BiH₃ : Increasing base strength.

Answer 1

On moving down the group from N to Bi, the atomic size increases, consequently the electron density on the central atom decreases and the basic strength decreases. Therefore, the increasing order of basic strength is as follow : BiH₃ < SbH₃ < AsH₃ < PH₃ < NH₃