Answer :
Final answer:
The difference in normal boiling points between CCl4 and CBr4 is because of the stronger London dispersion forces in CBr4 due to larger bromine atoms, thus requiring more energy to reach the boiling point.
Explanation:
The normal boiling points of compounds like CCl4 (77ºC) and CBr4 (190ºC) differ significantly due to variances in intermolecular forces. In these cases, the larger bromine atoms in CBr4 contribute to stronger London dispersion forces when compared to the smaller chlorine atoms in CCl4. This leads to a higher boiling point for CBr4 because more energy is required to overcome these forces to transition from a liquid to a gaseous state.
