To determine which of the given solutions forms an ideal solution, we need to understand the characteristics of an ideal solution. An ideal solution is one that follows Raoult's law, has no change in enthalpy upon mixing (ΔH_mix = 0), and shows no deviation from ideal behavior.
### Step-by-Step Solution:
1. **Understand Ideal Solutions**:
- An ideal solution is one that obeys Raoult's law throughout the entire concentration range. This means that the vapor pressure of each component in the solution is equal to the vapor pressure of the pure component multiplied by its mole fraction in the solution.
- For an ideal solution, the change in enthalpy (ΔH_mix) upon mixing is zero, indicating that there is no heat absorbed or released during the mixing process.
- Ideal solutions typically consist of similar types of molecules, which means they do not form ions or exhibit strong intermolecular forces that would cause deviations.
2. **Identify the Types of Solutions**:
- The question provides two types of solvents and solutions: polar and non-polar.
- Polar solutions tend to dissociate into ions (e.g., water), leading to deviations from ideal behavior.
- Non-polar solutions do not dissociate into ions and generally follow ideal behavior.
3. **Examine the Given Options**:
- **Option 1: Benzene and Toluene**: Both are non-polar solvents and do not dissociate. They are likely to form an ideal solution.
- **Option 2: n-Hexane**: This is also a non-polar solvent and does not dissociate, suggesting it could form an ideal solution.
- **Option 3: Ethyl Bromide and Ethyl Iodide**: These are polar solvents that can dissociate, which indicates they may not form an ideal solution due to deviations.
- **Option 4: All of the Above**: This option suggests that all combinations form ideal solutions.
4. **Conclusion**:
- Since both benzene and toluene, as well as n-hexane, are non-polar and do not dissociate, they are likely to form ideal solutions.
- Ethyl bromide and ethyl iodide, being polar, may not form ideal solutions due to their tendency to dissociate.
- Therefore, the correct answer is that the first two options (benzene and toluene, and n-hexane) form ideal solutions, while the third option does not.
### Final Answer:
The ideal solutions are formed by benzene and toluene, and n-hexane. The correct answer is **Option 1 and Option 2**.
