In which of the following reactions, hydrogen is acting as an oxidizing agent?

Question

In which of the following reactions, hydrogen is acting as an oxidizing agent? (A) With Li to form LiH (B) With I2 to give HI (C) With S to give H2S (D) None of the above

Tardigrade Admin · Accepted Answer

Oxidising agent is one which undergoes reduction. Decreasing in oxidation number shows reduction. Find oxidation number in all given reactions to decide in which of them hydrogen is oxidising agent.
(a)

L i + H 0_{2} ⟶ 2 L i + 1 H - 1

Oxidation number of hydrogen is decreasing from 0 to

- 1

.
So

H_{2}

is acting as oxidising agent in this reaction.
(b)

H 0_{2} + I_{2} ⟶ 2 H I +

∵

Oxidation number of hydrogen is increasing.

H_{2}

is not acting as oxidising agent in this reaction.
(c)

H_{2} 0 + S ⟶ H + 1_{2} S

∵

Oxidation number of hydrogen is increasing

∴ H_{2}

is not acting as oxidising agent in this reaction.

Q. In which of the following reactions, hydrogen is acting as an oxidizing agent?

With $L i$ to form $L i H$

With $I_{2}$ to give $H I$

With $S$ to give $H_{2} S$

None of the above

Q. In which of the following reactions, hydrogen is acting as an oxidizing agent?

With Li to form LiH

With I2​ to give HI

With S to give H2​S

None of the above

With $L i$ to form $L i H$

With $I_{2}$ to give $H I$

With $S$ to give $H_{2} S$