Question

Explain the following briefly:

The boiling point of bromoethane is higher than that of chloroethane.

Answer 1

1. The boiling point of bromomethane is higher than that of chloroethane due to stronger intermolecular forces. 
2. Both bromoethane (C₂H₅Br) and chloroethane (C₂H₅Cl) are polar covalent compounds.
3. Their molecules are held together by intermolecular van der Waals’ forces.
4. The molecular mass of bromoethane (≈109 g/mol) is higher than that of chloroethane (≈64.5 g/mol).
5. Higher molecular mass means larger molecular size and stronger London dispersion forces in bromoethane.
6. Therefore, more energy is required to separate bromoethane molecules than chloroethane molecules.

Hence, the boiling point of bromoethane is higher than that of chloroethane.