Explanation:

In order to understand this question, we need to first understand what Raoult's law is. Raoult's law states that the partial pressure of a component of an ideal solution is equal to the product of the vapor pressure of that component in its pure state and its mole fraction in the solution. According to Raoult's law, the vapor pressure of a component in a solution should be directly proportional to its mole fraction.

Negative Deviation from Raoult's Law:

When the vapor pressure of a component in a solution is lower than expected based on Raoult's law, it is known as negative deviation. This means that the molecules of the components in the solution tend to attract each other more strongly than in their pure states. Negative deviation occurs when the intermolecular forces of attraction between the molecules in the solution are stronger than the forces between the molecules of the pure components.

Explanation of the Given Options:

a) Acetone and Ethanol: Both acetone and ethanol are polar compounds and they have similar intermolecular forces of attraction. Therefore, they are likely to follow Raoult's law and show positive deviation.

b) Carbon tetrachloride and Chloroform: Carbon tetrachloride and chloroform are nonpolar compounds and they have similar intermolecular forces of attraction. Therefore, they are likely to follow Raoult's law and show positive deviation.

c) Acetone and Chloroform:

Acetone is a polar compound, while chloroform is a nonpolar compound. They have different intermolecular forces of attraction. Acetone has dipole-dipole interactions, while chloroform has London dispersion forces. These different intermolecular forces can lead to negative deviation from Raoult's law.

In the solution of acetone and chloroform, the acetone molecules will have a stronger attraction towards each other due to dipole-dipole interactions. Similarly, the chloroform molecules will have a stronger attraction towards each other due to London dispersion forces. These stronger intermolecular forces will reduce the vapor pressure of both acetone and chloroform in the solution, leading to negative deviation from Raoult's law.

Therefore, option c) Acetone and Chloroform is an example of negative deviation from Raoult's law.