Question

The strongest reducing agent among the following is:

• A. SbH$_3$
• B. NH$_3$
• C. BiH$_3$
• D. PH$_3$

Hint:

In a group, reducing character increases down the group due to an increase in atomic size and a decrease in bond strength.

Answer 1

The Correct Option is C

Step 1: Reducing Agent Strength Explained
A reducing agent facilitates oxidation by donating electrons. - Reducing agent strength correlates positively with movement down a group in the periodic table. - This trend is attributed to increasing atomic size and a weakening of the central atom-hydrogen bond, which facilitates electron donation. 
Step 2: Analyzing Group 15 Hydride Trends 
- Group 15 hydrides are represented as: \( NH_3, PH_3, AsH_3, SbH_3, BiH_3 \). - The order of increasing reducing character is observed as follows: \[ NH_3<PH_3<AsH_3<SbH_3<BiH_3 \] - Consequently, BiH$_3$ exhibits the highest reducing agent strength among the listed compounds.