Among the following , select the pair that does not form an ideal solution

Options

A. Carbon tetrachloride and Silicon tetrachloride
B. Chlorobenzene and Bromobenzene
C. Chloroform and Carbon tetrachloride
D. Benzene and toluene

Answer

To solve the question of which pair does not form an ideal solution, we need to understand the characteristics of ideal solutions and the factors that influence their formation.

### Step-by-Step Solution:

1. **Understanding Ideal Solutions**:
- Ideal solutions are formed when the enthalpy of mixing (ΔH_mix) is zero. This means that there is no heat absorbed or released when the components are mixed.
- Additionally, the intermolecular forces between the different components should be similar to those in the pure components.

2. **Analyzing the Given Pairs**:
- We need to evaluate the pairs provided in the question to determine their compatibility in forming an ideal solution.

3. **Pair 1: Carbon Tetrachloride (CCl4) and Silicon Tetrachloride (SiCl4)**:
- Both are tetrahedral in structure and have similar polarities. Therefore, they can form an ideal solution.

4. **Pair 2: Chlorobenzene (C6H5Cl) and Bromobenzene (C6H5Br)**:
- Both compounds are aromatic and have similar structures. Thus, they can also form an ideal solution.

5. **Pair 3: Chloroform (CHCl3) and Carbon Tetrachloride (CCl4)**:
- Chloroform is polar due to the presence of hydrogen, while carbon tetrachloride is non-polar. The difference in polarity suggests that they will not mix ideally, leading to a non-ideal solution.

6. **Conclusion**:
- Among the pairs analyzed, chloroform and carbon tetrachloride do not form an ideal solution due to their differing polarities. Therefore, the correct answer is the pair of chloroform and carbon tetrachloride.

### Final Answer:
The pair that does not form an ideal solution is **Chloroform (CHCl3) and Carbon Tetrachloride (CCl4)**.

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