The statement that is INCORRECT about Ellingham diagram is

Options

A. provides idea about the reaction rate.
B. provides idea about free energy change
C. provides idea about changes in the phases during the reaction.
D. provides idea about reduction of metal oxide.

Answer

To solve the question regarding the incorrect statement about the Ellingham diagram, we will analyze the properties and implications of the Ellingham diagram step by step.

### Step-by-Step Solution:

1. **Understanding the Ellingham Diagram**:
The Ellingham diagram is a graphical representation that shows the change in Gibbs free energy (ΔG) for the formation of oxides from metals as a function of temperature. It is primarily used to assess the thermodynamic feasibility of reduction reactions.

**Hint**: Remember that the Ellingham diagram is focused on thermodynamics, not kinetics.

2. **Thermodynamic Feasibility**:
The diagram indicates whether a reaction is thermodynamically favorable (ΔG < 0) at a given temperature. This means it can help predict if a metal can be reduced from its oxide using a specific reducing agent.

**Hint**: Look for statements that relate to thermodynamic properties versus kinetic properties.

3. **Kinetics vs. Thermodynamics**:
One crucial aspect of the Ellingham diagram is that it does not provide information about the rate of reactions (kinetics). It only indicates whether a reaction can occur under certain conditions, not how fast it will occur.

**Hint**: Identify any options that mention reaction rates or kinetics.

4. **Analyzing the Options**:
- **Option 1**: "Graph gives about the change of phase." - This is generally correct as the diagram can indicate phase changes related to the formation of oxides.
- **Option 2**: "Graph gives about the rate of reaction." - This is incorrect because the Ellingham diagram does not provide information on the rate of reactions; it only indicates thermodynamic feasibility.
- **Option 3**: "Graph gives about free energy." - This is correct as the diagram indeed represents changes in free energy for the formation of oxides.

**Hint**: Compare each statement with the fundamental principles of the Ellingham diagram.

5. **Conclusion**:
The incorrect statement regarding the Ellingham diagram is the one that mentions the rate of reaction. Therefore, the answer is **Option 2**.

### Summary of the Solution:
The Ellingham diagram is a thermodynamic tool that does not provide information about the kinetics of reactions. The incorrect statement about the Ellingham diagram is that it gives information about the rate of reaction.