Which of the following has the highest boiling point?

Tetrachloromethane

The correct answer is option 4.  Tetrachloromethane.

The boiling point of a compound depends on the strength of the intermolecular forces between the molecules. The stronger the intermolecular forces, the higher the boiling point.

In the case of the chloromethanes, the intermolecular forces are van der Waals forces. The number of van der Waals forces increases as the number of chlorine atoms increases. Therefore, tetrachloromethane, which has the most chlorine atoms, has the strongest intermolecular forces and the highest boiling point.

The boiling points of the chloromethanes are as follows:

• Chloromethane (CH₃Cl): -24.0 °C
• Dichloromethane (CH₂Cl₂): 40.0 °C
• Trichloromethane (CHCl₃): 61.2 °C
• Tetrachloromethane (CCl₄): 76.7 °C