Question

The correct order of stability of following carbocations is:
$\left(A\right)\underset{1^o}{\underset{\text{Methyl}\text{carbocation}}{\stackrel{+}{C}{H}_3}\left(B\right)C{F}_3-C{H}_2^{+}\left(C\right)C{F}_3-\underset{\underset{\underset{2^o}{C{F}_3}}{|}}{C}{H}^{+}}\left(D\right)C{F}_3-\underset{\underset{\underset{3^o}{C{F}_3}}{|}}{\stackrel{\stackrel{C{F}_3}{|}}{C^{+}}}|$

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

Answer 1

The correct option is A $A>B>C>D$

As the number of electron withdrawing groups increases $(-C{F}_3)$, the stability of carbocation decreases because an electron withdrawing group will pull the electron density from the carbocation carbon towards itself.
Hence the correct order of stability is $A>B>C>D$