Question

Which of the following represents the correct order of stability of the given carbocations?

Options

• \[\begin{array}{cc}
  \phantom{.......}|\\
  \ce{F3\overset{+}{C} > F3C - \overset{+}{C} > \overset{+}{C}H3}\\
  \phantom{.......}|
  \end{array}\]

• \[\begin{array}{cc}
  \phantom{.......}|\\
  \ce{H3\overset{+}{C} > F3C - \overset{+}{C} > F3\overset{+}{C}}\\
  \phantom{.......}|
  \end{array}\]

• \[\begin{array}{cc}
  |\phantom{........}\\
  \ce{F3C - \overset{+}{C} > F3\overset{+}{C} > H3\overset{+}{C}}\\
  |\phantom{........}
  \end{array}\]

• \[\begin{array}{cc}
  |\phantom{........}\\
  \ce{F3C - \overset{+}{C} > H3\overset{+}{C} > F3\overset{+}{C}}\\
  |\phantom{........}
  \end{array}\]

Answer 1

\[\begin{array}{cc}
\phantom{.......}|\\
\ce{H3\overset{+}{C} > F3C - \overset{+}{C} > F3\overset{+}{C}}\\
\phantom{.......}|
\end{array}\]

Explanation:

−I group destabilizes carbocation, and the inductive effect decreases as carbon chain length increases.