Question

The weakest reducing agent among the hydrides of Group15 elements

Answer 1

The hydrides of  Group15 elements are ( NH₃ , PH₃ , AsH₃ , SbH₃ , BiH₃).

Among these the weakest reducing agent is Ammonia(NH₃)

The reducing nature of a hydride is inversely proportional to the stability of a hydride. Since a very stable hydride does not loose its hydrogen ion, hence the reducing characteristics will be very least as compared to others.

In Ammonia(NH₃), the size of nitrogen ion is small as compared to other group 15 elements, so the bond between nitrogen and hydrogen is very strong. Hence it does not lose hydrogen ions easily. So Ammonia(NH₃) is the weakest reducing agent.

Answer 2

Ammonia is the weakest reducing agent among the hydrides of Group15 elements

EXPLANATION:

The hydrides of the Group 15 elements are$N H_{3}, P H_{3}, A s H_{3}, S b H_{3}, B i H_{3}$

• The reducing ability of the hydrides depends upon the hydride stability.

• The 'greater' the unstability of the hydride, 'greater' is the reducing ability.

In ammonia, the size of the Nitrogen ion is smaller compared to all the other ions in the group. The covalent bond between Nitrogen and Hydrogen is very strong, so hydrogen ions cannot be lost easily. Therefore, Ammonia is the weakest reducing agent. The reducing ability increases from 'Ammonia' to 'Bismuthine'.