Ncert Exercises & Solutions

The correct statement among the following regarding the reaction of FeO below point A in the above diagram is:

1. Reduced by carbon monoxide only.

2. Reduced by both carbon monoxide and carbon.

3. Reduced by carbon only.

4. Not reduced by both carbon and carbon monoxide.

HINT: Below point ‘A’ FeO can be reduced by carbon monoxide only.

Explanation:

Any metal will reduce oxide of other metals which lie above it in the Ellingham diagram because free energy change will become more negative.

Below point A Gibbs free energy change for the formation of

{CO}_{2}

from

CO (∆ G_{CO, {CO}_{2}}^{°})

has lower value (more negative value) than Gibbs free energy change for the formation of

FeO (∆ G_{Fe, FeO})

Hence, FeO will be reduced by CO only below point A.