Question

Which of the following compounds have higher boiling points?

• A. 1-Chlorobutane
• B. 1-Chloropropane
• C. Isopropyl Chloride
• D. All of these

Answer 1

The correct option is A

1-Chlorobutane

Explanation for correct option:

(A) 1-Chlorobutane

Relation of boiling point with alkyl chain:

• The boiling point increases with an increase in the number of carbons in an alkyl chain.
• The boiling point decreases with branching in the carbon chain due to a decrease in surface area, hence intermolecular force between molecules also decreases.
• 1-Chlorobutane has the longest carbon chain and hence has the highest boiling point.

Structure of 1-Chlorobutane:

Explanation for incorrect options

(B) 1-Chloropropane

• Shorter alkyl chains have a lower boiling point than alkyl halides with more carbon atoms.
• The structure of 1-Chloropropane is given below:

(C) Isopropyl Chloride

• Branched alkyl halides have a lower boiling point than unbranched ones.
• The structure of Isopropyl Chloride is given below:

Hence, option (A) i.e. 1-Chlorobutane is correct.