The system that forms maximum boiling azeotrope is: - (a)- acetone - chloroform(b)- ethanol - acetone (c)- n-hexane – n-heptane(d)- carbon disulfide – acetone.

To determine which pair of compounds forms a maximum boiling azeotrope, let's briefly discuss what an azeotrope is. An azeotrope is a mixture of two or more liquids that has a constant boiling point and composition throughout the distillation process. A maximum boiling azeotrope is a mixture that boils at a higher temperature than either of the pure components.

Analyzing the Given Options
Acetone - Chloroform:

This mixture forms a minimum boiling azeotrope, not a maximum. The azeotrope forms at about 56.5 °C, which is lower than both pure components.
Ethanol - Acetone:

This combination also forms a minimum boiling azeotrope. The boiling point of the azeotrope is around 56.5 °C, which is lower than both components.
n-Hexane - n-Heptane:

These two form a non-azeotropic mixture, meaning they do not form a constant boiling point mixture. The boiling points are about 68.7 °C for n-hexane and 98.4 °C for n-heptane.
Carbon Disulfide - Acetone:

This pair forms a maximum boiling azeotrope. The boiling point of the azeotrope is higher than that of either pure component.
Conclusion
Based on the analysis, the correct answer is (d) Carbon Disulfide - Acetone, as this pair forms a maximum boiling azeotrope.

Explanation
In summary:

A maximum boiling azeotrope occurs when the interaction between the two components is strong enough to increase the boiling point above that of the individual components.
In contrast, a minimum boiling azeotrope occurs when the mixture has a lower boiling point than either component, often due to favorable interactions that stabilize the mixture.
Thus, the maximum boiling azeotrope is formed by carbon disulfide and acetone.