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

Options

A. `DeltaV = 0 `
B. `DeltaH = DeltaV ne 0`
C. `DeltaH = 0 `
D. it must obey Raoult's law

Explanation

To solve the question, we need to analyze the properties of an ideal solution and identify which statement is not correct.

### Step-by-Step Solution:

1. **Understanding Ideal Solutions**:
An ideal solution is one that follows Raoult's law throughout the entire concentration range. This means that the vapor pressure of each component in the solution is directly proportional to its mole fraction.

2. **Raoult's Law**:
According to Raoult's law, the change in volume (ΔV_mix) upon mixing two components is zero for an ideal solution. This means that the total volume of the solution is equal to the sum of the volumes of the individual components before mixing.

3. **Enthalpy of Mixing**:
For an ideal solution, the enthalpy of mixing (ΔH_mix) is also zero. This indicates that there is no heat absorbed or released when the two components are mixed.

4. **Analyzing the Options**:
- **Option 1**: ΔV_mix = 0. This is correct for an ideal solution.
- **Option 2**: ΔH = ΔV, not equal to 0. This is incorrect because, for an ideal solution, ΔH_mix = 0 and ΔV_mix = 0. Therefore, ΔH cannot be equal to ΔV if both are zero.
- **Option 3**: ΔH = 0. This is correct for an ideal solution.
- **Option 4**: Statement consistent with Raoult's law. This is correct.

5. **Conclusion**:
The statement that is not correct is Option 2, which claims that ΔH is equal to ΔV and not equal to 0.

### Final Answer:
The option that is not correct for an ideal solution is **Option 2**.