Increasing order of reducing power of following hydrides would be

1. \(SbH_3\)
2. \(AsH_3\)
3. \(NH_3\)
4. \(PH_3\)
5. \(BiH_3\)

Choose the correct answer from the options given below:

C < D < B < A < E

The reducing character of a compound depends upon the ease of production of the hydrogen atom. As we move down the group, the bond strength of group 15 hydrides decreases due to an increase in the size of atoms. So, as the bond strength decrease, the ease to produce increase along with the group. Hence, the reducing character of group 15 hydrides increases down the group.

Therefore, the trend of the reducing strength is:

\(NH_3 < PH_3 < AsH_3 < SbH_3 < BiH_3\) i.e., option (2) C < D < B < A < E