Which of the following will form an ideal solution ?

Options

A. `C_(2)H_(5)OH` and water
B. `HNO_(3)` and water
C. `CHCl_(3) and CH_(3)COCH_(3)`
D. `C_(6)H_(6) and C_(6)H_(5)CH_(3)`

Answer

To determine which of the given pairs will form an ideal solution, we need to understand the conditions that define an ideal solution.

### Step-by-step Solution:

1. **Understanding Ideal Solutions**:
An ideal solution is formed when the interactions between the molecules of the different components (A and B) are similar to the interactions between the molecules of each component (A-A and B-B). Mathematically, this can be expressed as:
\[ A-A \text{ interaction} = B-B \text{ interaction} = A-B \text{ interaction} \]

2. **Analyzing the Given Options**:
We have four pairs to analyze:
- Option A: C2H5OH (Ethanol) and Water
- Option B: H2O (Water) and HNO3 (Nitric Acid)
- Option C: CHCl3 (Chloroform) and CH3COCH3 (Acetone)
- Option D: C6H5H (Benzene) and C6H5CH3 (Toluene)

3. **Evaluating Each Pair**:
- **Option A (C2H5OH and Water)**: Ethanol and water form hydrogen bonds, which means their interactions are not similar to their own interactions, so they do not form an ideal solution.
- **Option B (H2O and HNO3)**: Water and nitric acid have strong ionic interactions, which again differ from their own interactions, thus not forming an ideal solution.
- **Option C (CHCl3 and CH3COCH3)**: Chloroform and acetone have different polarities and do not exhibit similar interactions, hence they do not form an ideal solution.
- **Option D (C6H5H and C6H5CH3)**: Benzene and toluene are both non-polar hydrocarbons and have similar types of interactions (London dispersion forces), making them likely to form an ideal solution.

4. **Conclusion**:
Based on the analysis, the pair that will form an ideal solution is **Option D: C6H5H (Benzene) and C6H5CH3 (Toluene)**.

### Final Answer:
**Option D: C6H5H and C6H5CH3 will form an ideal solution.**