Question

Which of the following hydride is not a reducing agent?

• A. ${\mathrm{H}}_2\mathrm{O}$
• B. ${\mathrm{H}}_2\mathrm{S}$
• C. ${\mathrm{H}}_2\mathrm{Te}$
• D. ${\mathrm{H}}_2\mathrm{Se}$

Answer 1

The correct option is A

${\mathrm{H}}_2\mathrm{O}$

Explanation for correct option

(A)${\mathrm{H}}_2\mathrm{O}$

Reducing agent

• A reducing agent is one that loses its electrons and gets oxidized in a chemical reaction.
• Metal or non-metal in an oxide cannot be oxidized when it is at its “maximum possible oxidation state.”

Reducing nature of Hydrides

• As the atomic size of the atom increases its tendency of donating electrons increases.
• On going down the group, the reducing nature of hydrides increases so the order is as follows:-
• ${\mathrm{H}}_2\mathrm{O}<{\mathrm{H}}_2\mathrm{S}<{\mathrm{H}}_2\mathrm{Se}<{\mathrm{H}}_2\mathrm{Te}$
• The bond strength of $\mathrm{O}-\mathrm{H}$ is high and the bond is not easy to break.
• So, ${\mathrm{H}}_2\mathrm{O}$is not a reducing agent.

Explanation for incorrect option

• All the hydrides accept ${\mathrm{H}}_2\mathrm{O}$ can act as a reducing agent. Hence, options (B), (C), (D) are incorrect.

Hence, option (A) is correct. ${\mathrm{H}}_2\mathrm{O}$is not a reducing agent.