A solution is non-ideal when

Options

A. `(Deltap)_(sol).ne 0`
B. `(DeltaH)_(sol)=0`
C. `(DeltaG)_(sol).lt0`
D. `(DeltaV)_(sol).=0`

Answer

To determine when a solution is considered non-ideal, we can analyze the conditions given in the question. Let's break down the parameters one by one.

### Step-by-Step Solution:

1. **Understanding Delta P (ΔP)**:
- ΔP is the change in partial pressure of the components in the solution. For an ideal solution, ΔP should be equal to 0. This means that the total partial pressure of the solution should equal the sum of the partial pressures of the individual components when they are in their pure states.
- If ΔP is not equal to 0, it indicates that the solution deviates from ideal behavior, thus it is classified as a non-ideal solution.

2. **Analyzing Delta H (ΔH)**:
- ΔH refers to the change in enthalpy during the mixing of solute and solvent. For an ideal solution, ΔH is typically 0, meaning no heat is absorbed or released during the mixing process.
- If ΔH is 0, it suggests that the solution behaves ideally. Therefore, if ΔH is not 0, it indicates non-ideal behavior, but if ΔH is 0, it does not confirm non-ideality.

3. **Considering Delta G (ΔG)**:
- ΔG is the change in Gibbs free energy. For an ideal solution, ΔG is usually negative during mixing, indicating that the process is spontaneous.
- If ΔG is less than 0, it suggests that the solution is behaving ideally. Thus, this condition does not indicate non-ideality.

4. **Evaluating Delta V (ΔV)**:
- ΔV represents the change in volume upon mixing. In non-ideal solutions, the volume can either increase or decrease due to interactions between solute and solvent.
- If ΔV is equal to 0, it suggests that the volume does not change upon mixing, which is a characteristic of ideal solutions. Therefore, this condition also does not indicate non-ideality.

### Conclusion:
Based on the analysis, a solution is classified as non-ideal when ΔP is not equal to 0. Thus, the correct answer is that a solution is non-ideal when **ΔP solution is not 0**.