Identify the pairs of compounds that represents chain isomerism.
I and III,
I and IV,
II and III,
II and IV,
II and IV,
V and VII,
VI and VII
Explanation:
Compounds having same molecular formula but vary in the length of the parent chain(as they are branched) is called chain isomerism. Compound I and II are linear (no branching) while III and IV are branched, so I and II are chain isomers with III and IV. Similarly, VII is ether with a branched alkyl group while V and VI are linear. So, VII is an isomer of both V and VI.