Question

Find out the order of stability between$\left(A\right)C{H}_3-C{H}_2-\underset{\underset{Br}{|}}{C}H-\stackrel{+}{C}H-C{H}_3$
$\left(B\right)C{H}_3-C{H}_2-\underset{\underset{I}{|}}{C}H-\stackrel{+}{C}H-C{H}_3$

• A. $A>B$
• B. $B>A$
• C. both have same stability
• D. can't predict

Answer 1

The correct option is B $B>A$

$-I$ and $-Br$ are electron withdrawing group. Therefore, it will decrease the stability of the carbocation.
more is the electronegativity of atom attached to the carbon more it will show -I effect and more it destablise the carbocation. Electronegativity order of atom is Br>I
Therefore, the order of stability of carbocation is:
$(C{H}_3-C{H}_2-\underset{\underset{Br}{|}}{C}H-\stackrel{+}{C}H-C{H}_3<C{H}_3-C{H}_2-\underset{\underset{I}{|}}{C}H-\stackrel{+}{C}H-C{H}_3$
Hence B is the correct option.