Which one of the following is non-ideal solution?

Options

A. Benzene + toluene
B. n-hexane + n-heptane
C. Ethyl bromide + ethyl iodide
D. `C""Cl_4 +CHCl_3`

Answer

To determine which of the following is a non-ideal solution, we need to understand the characteristics of ideal and non-ideal solutions.

### Step-by-Step Solution:

1. **Understanding Ideal Solutions**:
- An ideal solution is one that follows Raoult's law at all concentrations, temperatures, and pressures.
- In an ideal solution, the interactions between solute-solute, solvent-solvent, and solute-solvent are similar. This means that the forces holding the molecules together are comparable.

2. **Characteristics of Non-Ideal Solutions**:
- Non-ideal solutions do not follow Raoult's law completely. They may show either positive or negative deviations.
- Positive deviation occurs when the vapor pressure of the solution is higher than predicted by Raoult's law, often due to weaker interactions between different molecules.
- Negative deviation occurs when the vapor pressure is lower than predicted, often due to stronger interactions between solute and solvent molecules compared to the interactions in the pure components.

3. **Analyzing the Given Options**:
- We need to analyze the interactions in the proposed solutions.
- For example, if we consider the mixture of carbon tetrachloride (CCl4) and chloroform (CHCl3):
- CCl4 has weak London dispersion forces.
- CHCl3 has stronger dipole-dipole interactions.
- When mixed, the interaction between CCl4 and CHCl3 results in dipole-induced dipole interactions, which are significant.

4. **Conclusion**:
- Since the interaction between CCl4 and CHCl3 is not similar to the interactions in the pure components, this mixture does not obey Raoult's law and is classified as a non-ideal solution.
- Therefore, the correct answer is that the mixture of CCl4 and CHCl3 is a non-ideal solution.

### Final Answer:
The non-ideal solution among the given options is the mixture of carbon tetrachloride (CCl4) and chloroform (CHCl3).

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