Question

In which of the following reactions have the underlined substance been reduced?

• A. $\underset{–}{Carbonmonoxide}+copperoxide\to carbondioxide+copper$
• B. $\underset{–}{Copperoxide}+hydrochloricacid\to copperchloride+water$
• C. $\underset{–}{Hydrogen}+ironoxide\to iron+water$
• D. $\underset{–}{Steam}+iron\to ironoxide+hydrogen$

Answer 1

The correct option is D $\underset{–}{Steam}+iron\to ironoxide+hydrogen$

In A) Carbon is oxidised from +2 oxidation state to +4 oxidation state.

In B) Copper neither undergoes oxidation nor reduction.

In C) Hydrogen is oxidised from 0 to +1 oxidation state.

In D) Hydrogen is reduced from +1 to 0 oxidation state.

So in D) reaction underlined substance undergoes reduction.