Question

Assertion (A): Butane and 2-methyl butane are homologues.

Reason (R): Butane is a straight chain alkene while 2-methyl butane is a branched chain alkene.

Options

• If both A and R are true, and R is the correct explanation of A.

• If both A and R are true, but R is not the correct explanation of A.

• If A is true, but R is false.

• If both A and R are false.

Answer 1

If A is true, but R is false.

Explanation:

Assertion (A) is true because butane (C₄H₁₀) and 2-methylbutane (C₅H₁₂) belong to the same homologous series of alkanes and differ from each other by a structural –CH₂ unit. However, Reason (R) is false because both compounds are fully saturated hydrocarbons containing only single bonds, making them alkanes, not alkenes. Because the reason incorrectly labels them as alkenes, statement R is completely false.