Which of the following is an example of a cyclic hydrocarbon?

Correct option is C

The correct answer is (c) Cyclohexane

Explanation:

• Hydrocarbons are categorized structurally into open-chain (aliphatic) and closed-chain (cyclic or ring) compounds.
• A cyclic hydrocarbon is one where the carbon atoms link tightly together to structurally form a closed ring.
• Cyclohexane (C_6H_{12}) consists precisely of six carbon atoms bonded covalently in a closed hexagonal ring structure, with each carbon uniquely bonded to two hydrogen atoms.
• Therefore, it functions as a classic example of a saturated cyclic hydrocarbon.

Information Booster:

• Cyclic hydrocarbons can be broadly saturated (containing only single bonds, like cyclohexane) or unsaturated (containing double bonds, like cyclohexene).
• Benzene (C_6H_6) is a highly special type of unsaturated cyclic hydrocarbon, known primarily as an aromatic compound due to its alternating double bonds.
• The naming of saturated cyclic hydrocarbons generally adds the prefix "cyclo-" before the corresponding alkane name.

Additional Knowledge:
Methane (Option a)

• Methane (CH_4) contains only a single carbon atom. It inherently cannot form a closed ring, and is the simplest straight-chain alkane.

Butane (Option b)

• Butane (C_4H_{10}) features four covalently bonded carbon atoms in a straight or branched open chain, rather than a closed ring.

Ethene (Option d)

• Ethene (C_2H_4) is the simplest alkene. It contains a rigid double bond but exists explicitly as an open-chain linear molecule, not a cycle.

So the correct answer is (c)