Question

Select the correct statements for Ellingham diagram.

• A. Any metal will reduce the oxide of other metals which lie above it in the Ellingham diagram
• B. According to the Ellingham diagram, Al will not reduce MgO at temperature below 1350${}^{\circ }$C
• C. According to the Ellingham diagram, Al will reduce MgO at temperature below 1350${}^{\circ }$C
• D. Any metal will not reduce the oxide of other metals which lie above it in the Ellingham diagram

Answer 1

Answer: (A), (B)

The correct options are
A Any metal will reduce the oxide of other metals which lie above it in the Ellingham diagram
B According to the Ellingham diagram, Al will not reduce MgO at temperature below 1350${}^{\circ }$C

Any metal will reduce the oxide of other metals which lie above it in the Ellingham diagram because the free energy will become more negative by an amount equal to the difference between the two graphs at that particular temperature.

Al metal can reduce the oxide of metal placed above it. Due to more negative free energy, Al can reduce Zn but not Mg below ${1350}^{o}C$. However, above ${1350}^{o}C$, Al can reduce Mg.

Hence, option A and B are correct.