Question

n-pentane and 2-methylbutane are a pair of
A. Enantiomers
B. Stereoisomers
C. Diastereomers
D. Constitutional isomers

Answer 1

Correct Answer - D
Constitutional isomerism or strcuture isomerism arises due to the difference in the manner in which the consituent atoms or groups are linked to one another within the molecule, without any reference to space.
The type of consitutional isomerism that exists between n-pentane and 2-methyl butane is chain isomerism.