Question

Which of the following statements is not correct about Ellingham diagram?

• A. It is the graph between $\Delta G^{\circ}$ and T for the formation of oxides
• B. Oxide with lower value of $\Delta G^{\circ}$ is more stable
• C. The choice of reducing agent can be predicted
• D. It tells us about the kinetics of the reduction process

Hint:

Thermodynamics tells you if a reaction is possible (feasibility), not how fast it goes (kinetics).

Answer 1

The Correct Option is D

Step 1: Remember what the Ellingham diagram shows.
It is a plot of the standard free energy change $\Delta G^{\circ}$ for forming metal oxides against temperature T. So option A is a true description.

Step 2: Check the stability point.
A more negative (lower) $\Delta G^{\circ}$ means the oxide forms more easily and is more stable. So option B is also true.

Step 3: Check the reducing agent point.
If one metal's line sits below another's at a given temperature, that lower metal can reduce the oxide above it. So the diagram does help pick a reducing agent. Option C is true.

Step 4: Spot the catch.
The diagram is built only on thermodynamics, which tells us whether a reaction can happen, not how fast. It says nothing about kinetics or rate. So option D is the wrong statement.

Step 5: Conclusion.
So the answer is that it tells us about the kinetics of the reduction process, which is not correct. \[ \boxed{\text{Option D}} \]