The system that forms maximum boiling azeotrope is

Options

A. acetone-chloroform
B. ethanol-acetone
C. n-hexane-n-heptane
D. carbon disulphide - acetone

Explanation

To determine the system that forms a maximum boiling azeotrope, we need to understand some key concepts about azeotropes and their behavior in solutions.

### Step-by-Step Solution:

1. **Understanding Azeotropes**:
- Azeotropes are mixtures of two or more liquids that boil at a constant temperature and maintain the same composition in the vapor phase as in the liquid phase.
- They can be classified into two types: maximum boiling azeotropes and minimum boiling azeotropes.

2. **Identifying Maximum Boiling Azeotropes**:
- A maximum boiling azeotrope is formed when the solution exhibits negative deviation from Raoult's law. This means that the vapor pressure of the solution is lower than predicted by Raoult's law, leading to a higher boiling point than that of either component.

3. **Analyzing Given Systems**:
- **Acetone and Chloroform**: This mixture shows negative deviation from Raoult's law and is known to form a maximum boiling azeotrope.
- **Ethanol and Acetone**: This mixture shows positive deviation, indicating it forms a minimum boiling azeotrope.
- **n-Hexane and n-Heptane**: This is an ideal solution, which does not form an azeotrope.
- **Carbon Disulfide and Acetone**: This mixture also shows positive deviation, indicating it forms a minimum boiling azeotrope.

4. **Conclusion**:
- From the analysis, the only mixture that forms a maximum boiling azeotrope is **Acetone and Chloroform**.

### Final Answer:
The system that forms a maximum boiling azeotrope is **Acetone and Chloroform**.

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