Question

Which of the following carbocation is the most stable?

Options

• \[\begin{array}{cc}
  \phantom{...}\ce{CH3}\\
  \phantom{......}|\phantom{...}+\phantom{}\\
  \ce{CH3 - C - CH2}\\
  |\\
  \phantom{..}\ce{CH3}
  \end{array}\]

• \[\begin{array}{cc}
  \phantom{..................}\ce{+}\\
  \ce{CH3 - CH2 - CH - CH2}\\
  \phantom{.....}|\\
  \phantom{.......}\ce{CH3}
  \end{array}\]

• \[\begin{array}{cc}
  \ce{+}\phantom{.......}\\
  \ce{CH3 - C - CH2 - CH3}\\
  |\phantom{.......}\\
  \ce{CH3}\phantom{.....}
  \end{array}\]

• \[\begin{array}{cc}
  \phantom{.......}\ce{+}\\
  \ce{CH3 - CH2 - C - CH3}\\
  \phantom{.......}|\\
  \phantom{.......}\ce{H}
  \end{array}\]

Answer 1

\[\begin{array}{cc}
\ce{+}\phantom{.......}\\
\ce{CH3 - C - CH2 - CH3}\\
|\phantom{.......}\\
\ce{CH3}\phantom{.....}
\end{array}\]

Explanation:

The hyperconjugation interaction and carbocation stability increase as the number of alkyl groups linked to the positively charged carbon atom increases.