Arrange the following in order of their increasing bond enthalpies?
(A) Methyl Fluoride
(B) Methyl Iodide
(C) Methyl Chloride
(D) Methyl Bromide
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → (B), (D), (C), (A)
The strength of a carbon–halogen bond depends on the size of the halogen atom. From fluorine to iodine the halogen atom becomes larger, its orbitals overlap less effectively with the orbital of carbon, and the C–X bond becomes longer and weaker.
With the given labels:
(B) methyl iodide < (D) methyl bromide < (C) methyl chloride < (A) methyl fluoride
Shortcut: The C–I bond (B) is the weakest and the C–F bond (A) is the strongest. Only Option (2) starts with (B) and ends with (A).
NCERT (2026-27 edition):
Nature of C-X Bond – …
Note: The same/similar question has been asked in different years by NTA as per the details given below:
| 2026 | 2025 | 2024 | 2023 | 2022 |
|---|---|---|---|---|
| 26-05 S1 14-05 S2 | – | – | – | – |