Exams › JEE Main › Chemistry

Among the following carbocations, which one is the most stable?

1. Cyclopentadienyl cation
2. Cycloheptatrienyl cation
3. Cyclopentenyl cation
4. None of these

Correct answer: Cycloheptatrienyl cation

Solution

The cycloheptatrienyl (tropylium) cation has 6 pi electrons in a planar, fully conjugated ring, satisfying the 4n+2 rule (n=1), making it aromatic and exceptionally stable. The cyclopentadienyl cation has 4 pi electrons (antiaromatic, unstable), and the cyclopentenyl cation is only an allylic cation.

Related JEE Main Chemistry questions

• Lactic acid loses its optical activity when the hydroxyl group is replaced by hydrogen because
• Which is the most suitable technique for separating a mixture of sugars?
• Which statement correctly compares the staggered and eclipsed conformations of ethane?
• Which statement correctly describes a common feature shared by optical and geometrical isomerism?
• Which substituent lowers the reactivity of a benzene ring toward electrophilic substitution, yet still mainly directs a new group to the ortho and para positions?
• Among the following substances, which has the greatest affinity for a proton?

⚔️ Practice JEE Main Chemistry free + battle 1v1 →