Question

Arrange the hydrides of group 15 in correct decreasing order of reducing nature:

• A. \( \text{NH}_3 > \text{PH}_3 > \text{AsH}_3 > \text{SbH}_3 > \text{BiH}_3 \)
• B. \( \text{PH}_3 > \text{AsH}_3 > \text{SbH}_3 > \text{BiH}_3 > \text{NH}_3 \)
• C. \( \text{AsH}_3 > \text{SbH}_3 > \text{BiH}_3 > \text{NH}_3 > \text{PH}_3 \)
• D. \( \text{BiH}_3 > \text{SbH}_3 > \text{AsH}_3 > \text{PH}_3 > \text{NH}_3 \)

Hint:

In the hydrides of group 15 elements, ammonia is the strongest reducing agent due to its small size and high electron density, while the reducing power decreases as we move down the group.

Answer 1

The Correct Option is A

The reducing power of the hydrides of group 15 elements decreases as we move down the group. Ammonia (\( \text{NH}_3 \)) is the strongest reducing agent, and the reducing nature decreases with BiH\(_3\), which is the weakest reducing agent. Thus, the correct answer is Option (A).