Boiling point is a measure of the temperature at which a substance changes from a liquid to a gas. It is influenced by several factors, including intermolecular forces and molecular weight. In this case, we are comparing the boiling points of different chloromethane compounds: chloromethane (CH3Cl), dichloromethane (CH2Cl2), trichloromethane (CHCl3), and tetrachloromethane (CCl4).

Intermolecular forces play a significant role in determining the boiling point of a compound. The stronger the intermolecular forces, the higher the boiling point. The main intermolecular force present in these chloromethane compounds is dipole-dipole interactions, which occur between the positive end of one molecule and the negative end of another molecule. These interactions are stronger in compounds with more chloro substituents.

1. Chloromethane (CH3Cl):
- It has one chlorine atom attached to the central carbon atom.
- The dipole moment of CH3Cl is 1.87 D.
- It has the lowest boiling point among the given options.

2. Dichloromethane (CH2Cl2):
- It has two chlorine atoms attached to the central carbon atom.
- The dipole moment of CH2Cl2 is 1.60 D.
- It has a higher boiling point than chloromethane.

3. Trichloromethane (CHCl3):
- It has three chlorine atoms attached to the central carbon atom.
- The dipole moment of CHCl3 is 1.04 D.
- It has a higher boiling point than dichloromethane.

4. Tetrachloromethane (CCl4):
- It has four chlorine atoms attached to the central carbon atom.
- The dipole moment of CCl4 is 0 D.
- It has the highest boiling point among the given options.

The increase in boiling point from chloromethane to tetrachloromethane is due to the increase in the number of chloro substituents, which leads to stronger dipole-dipole interactions. Tetrachloromethane has the highest boiling point because it has the most chlorine atoms and therefore the strongest dipole-dipole interactions.