Chemistry · PYQ NEET UG 2021
हिन्दीThe CORRECT sequence of bond enthalpy of 'C–X' bond is _______.
View Answer & Solution
Correct answer · Option C
\( \mathrm{CH}_{3}-\mathrm{Cl}>\mathrm{CH}_{3}-\mathrm{F}>\mathrm{CH}_{3}-\mathrm{Br}>\mathrm{CH}_{3}-\mathrm{I} \)
Explanation
Due to small size and electron-electron repulsion of lone pairs in fluorine, the C-F bond is abnormally weak compared to C-Cl, giving the bond enthalpy order: \( \mathrm{CH}_{3}-\mathrm{Cl}>\mathrm{CH}_{3}-\mathrm{F}>\mathrm{CH}_{3}-\mathrm{Br}>\mathrm{CH}_{3}-\mathrm{I} \).