Question

The correct order for homolytic blood dissociation energies ($\Delta H$ in $kcal/mol$) for ${CH}_4\left(A\right),C_2{H}_6\left(B\right),{CH}_{3}Br\left(C\right)$ is

• A. $C>B>A$
• B. $B>C>A$
• C. $C>A>B$
• D. $A>B>C$

Answer 1

Answer: (A)

$C>B>A$

Since size of Bromine is more than Hydrogen, as a result of this $C-O$ bond is weaker than $C-H$ bond and $C-Br$ bond readily cleaves before $C-H$ bond or $C-C$ bond cleaver.