Question

Which of the following compound has the highest boiling point?

• A. 1-bromohexane
• B. 2-bromo-4-methylpentane
• C. 2-bromo-3-methylpentane
• D. All have equal boiling point

Answer 1

The correct option is A 1-bromohexane


For the same molar mass, as branching increases, the overall surface area decreases. This leads to a reduction in the intermolecular forces (London dispersion forces), thereby decreasing boiling point.
2-bromo-3-methylpentane and 2-bromo-4-methylpentane are branched. So, their surface area is lower than that of 1-bromohexane. Thus, they have lower boiling point than 1-bromohexane.