Identify the pairs of compounds that represents chain isomerism.
Chain isomers have the same molecular formula, but the way their carbon atoms are joined together differs from isomer to isomer. Alkane molecules with four or more carbon atoms have chain isomers. In these isomers, the carbon atoms are bonded together in different ways to produce branches.
Therefore, compounds I and III, I and IV, II and III and II and IV represent chain isomerism.