For an ideal solution which one of the following is not correct:

Options

A. `Delta V = 0`
B. `Delta H = Delta Vne 0`
C. `DeltaH = 0`
D. It must obey Raoult's law .

Explanation

To solve the question regarding the properties of an ideal solution, we need to analyze the characteristics of ideal solutions and identify which statement among the options is incorrect.

### Step-by-Step Solution:

1. **Understanding Ideal Solutions**:
- An ideal solution is one where the interactions between the molecules of different components are similar to the interactions between the molecules of the same component.

2. **Properties of Ideal Solutions**:
- The change in enthalpy (ΔH) upon mixing is zero (ΔH_mixing = 0).
- The change in volume (ΔV) upon mixing is also zero (ΔV_mixing = 0).
- The vapor pressure of each component in the solution follows Raoult's Law.

3. **Analyzing the Options**:
- We need to evaluate the given options to find out which one does not conform to the properties of an ideal solution.
- Common statements about ideal solutions include:
- ΔH_mixing = 0
- ΔV_mixing = 0
- The activity coefficients of the components are equal to 1.

4. **Identifying the Incorrect Statement**:
- If one of the options states that ΔH_mixing is not equal to zero or ΔV_mixing is not equal to zero, that would be the incorrect statement regarding ideal solutions.
- Based on the video transcript, it appears that the incorrect statement is about ΔH and ΔV not being zero.

5. **Conclusion**:
- Therefore, the option that states ΔH_mixing or ΔV_mixing is not equal to zero is the one that is incorrect for an ideal solution.

### Final Answer:
The incorrect statement regarding an ideal solution is that ΔH_mixing or ΔV_mixing is not equal to zero.