Benzene and toluene form an ideal solution at room temperature. Which Of the following is not true for this process?

Options

A. `DeltaV_(mix)=0`
B. `DeltaH_(mix)=0`
C. `DeltaS_(mix) for system=0`
D. `DeltaG_(mix)lt 0`

Answer

To determine which statement is not true regarding the formation of an ideal solution of benzene and toluene, we need to review the characteristics of ideal solutions.

### Step-by-step Solution:

1. **Understanding Ideal Solutions**:
Ideal solutions are those that follow Raoult's law perfectly. The properties of ideal solutions include:
- The enthalpy of mixing (ΔH_mixing) is zero.
- The volume of mixing (ΔV_mixing) is also zero.
- The Gibbs free energy of mixing (ΔG_mixing) is less than or equal to zero.

2. **Analyzing the Given Options**:
We need to evaluate the statements provided in the options to identify which one is not true. The options typically relate to the properties of the solution, such as ΔH_mixing, ΔV_mixing, and ΔG_mixing.

3. **Evaluating ΔH_mixing**:
For an ideal solution, ΔH_mixing = 0. This means that there is no heat absorbed or released during the mixing process.

4. **Evaluating ΔV_mixing**:
Similarly, for an ideal solution, ΔV_mixing = 0. This indicates that the total volume before and after mixing remains unchanged.

5. **Evaluating ΔG_mixing**:
For an ideal solution, ΔG_mixing should be less than or equal to zero. This means that the mixing process is spontaneous.

6. **Identifying the Incorrect Statement**:
If one of the options states that ΔG_mixing is greater than zero or any other incorrect assertion about ΔH_mixing or ΔV_mixing, that option will be the answer to the question.

7. **Conclusion**:
Based on the analysis, the statement that is not true is likely the one that contradicts the established properties of ideal solutions.

### Final Answer:
The statement that is not true for the process of benzene and toluene forming an ideal solution is that ΔG_mixing is greater than zero.