Question

What is the correct boiling point order of the following haloalkanes? \[ \text{i) 2-chloro 2-methylpropane} \quad \text{ii) 1-Cholobutane} \quad \text{iii) 2-Chlorobutane} \]

• A. i>ii>iii
• B. ii>iii>i
• C. i<ii<iii
• D. iii>ii>i

Hint:

The boiling point of haloalkanes increases with molecular size and the straightness of the chain, as longer chains have stronger London dispersion forces.

Answer 1

The Correct Option is B

- The boiling points of haloalkanes depend on their molecular size and structure.
- 1-Chlorobutane (ii) has the highest boiling point because it is a straight-chain molecule and has more surface area for intermolecular forces.
- 2-Chlorobutane (iii) has a lower boiling point than 1-chlorobutane because it is a branched structure, which results in weaker intermolecular forces.
- 2-chloro-2-methylpropane (i) has the lowest boiling point due to its compact, branched structure, which results in the weakest intermolecular forces.
Thus, the correct answer is (2) ii>iii>i.