All form ideal solution except

Options

A. `C_(6)H_(6)` and `C_(6)H_(5)CH_(3)`
B. `C_(2)H_(5)Cl` and `C_(2)H_(5)l`
C. `C_(6)H_(5)Cl` and `C_(6)H_(5)Br`
D. `C_(2)H_(5)l` and `C_(2)H_(5)OH`

Explanation

To determine which of the given solutions does not form an ideal solution, we need to understand the concept of ideal solutions and Raoult's law.

### Step-by-Step Solution:

1. **Understanding Ideal Solutions**:
- An ideal solution is one that obeys Raoult's law throughout the entire range of concentrations. Raoult's law states that the vapor pressure of a solvent in a solution is equal to the vapor pressure of the pure solvent multiplied by its mole fraction in the solution.
- Ideal solutions are typically formed when both components are similar in nature (both polar or both non-polar).

2. **Identifying Non-Ideal Solutions**:
- Non-ideal solutions are formed when there is a significant difference in the polarity of the components. For example, mixing a polar solvent with a non-polar solvent will lead to a non-ideal solution.

3. **Analyzing the Options**:
- **Option A**: C6H6 (Benzene) and C6H5CH3 (Toluene)
- Both are hydrocarbons and non-polar. Therefore, this mixture is ideal.
- **Option B**: C2H5Cl (Ethyl Chloride) and C2H5I (Ethyl Iodide)
- Both are alkyl halides and are considered non-polar. Therefore, this mixture is also ideal.
- **Option C**: C6H5Cl (Chlorobenzene) and C6H5Br (Bromobenzene)
- Both are non-polar aromatic compounds. Hence, this mixture is ideal as well.
- **Option D**: C2H5I (Ethyl Iodide) and C2H5OH (Ethanol)
- Ethyl Iodide is non-polar while Ethanol is polar. The significant difference in polarity means this mixture will not obey Raoult's law and thus is a non-ideal solution.

4. **Conclusion**:
- Based on the analysis, **Option D (C2H5I and C2H5OH)** is the correct answer as it does not form an ideal solution.

### Final Answer:
**Option D: C2H5I and C2H5OH do not form an ideal solution.**

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