Q44 - Organic molecules

The correct answer is C) An alkene.

Read the name: eth- means 2 carbons and -ene means a C=C double bond. Ethene, CH₂=CH₂, is the simplest alkene.

A) Incorrect: Ethene very much exists: it is used to make polyethylene and is a plant hormone that ripens fruit.

B) Incorrect: A diene has two C=C double bonds. Ethene has only one.

C) Correct: One C=C double bond makes ethene an alkene.

D) Incorrect: An alkyne has a triple bond. The two-carbon alkyne is ethyne (HC≡CH).

E) Incorrect: An alkenyne would need both a double and a triple bond.