Question

Ellingham diagram is a plot of _ _ _.

• A. $\Delta_f H^\circ$ versus temperature
• B. $\Delta_r G^\circ$ versus time
• C. $\Delta_r G^\circ$ versus temperature
• D. $\Delta_f H^\circ$ versus time

Hint:

Ellingham diagram always uses Gibbs free energy vs temperature, not enthalpy or time

Answer 1

The Correct Option is C

Step 1: Purpose of the Ellingham diagram.
It is used in metallurgy to judge whether a metal oxide can be reduced at a given temperature.

Step 2: What is plotted.
The graph shows the standard Gibbs energy of formation of oxides against temperature.

Step 3: Answer.
\[ \boxed{\Delta_r G^\circ \text{ versus temperature}} \]