Arrange the following in order of increasing boiling points.
(A) Bromomethane
(B) Bromoform
(C) Chloromethane
(D) Dibromomethane
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → (C), (A), (D), (B)
Boiling point of haloalkanes increases with:
- Molecular mass
- Number of halogen atoms
- Strength of intermolecular (London dispersion) forces
Let’s compare:
- (C) Chloromethane (CH₃Cl) → lowest molar mass
- (A) Bromomethane (CH₃Br) → heavier than CH₃Cl
- (D) Dibromomethane (CH₂Br₂) → two Br atoms → higher b.p.
- (B) Bromoform (CHBr₃) → three Br atoms → highest b.p.
Increasing order of boiling points: $(C) < (A) < (D) < (B)$
(C) Chloromethane < (A) Bromomethane < (B) Bromoform <(D) Dibromomethane