Note: Consider structures I to VII and answer the question Which of the above compounds form pairs of metamers?

When two or more compounds having same molecular formula but different alkyl groups on either side of the functional group, the compounds are called metamers. In the given structures V and VI, VI and VII and V and Vll form a pair of metamers because alkyl groups are different on either side of the functional group - O - .

Note: Consider structures I to VII and answer the question Identify the pairs of compounds which are functional group isomers.

Two or more compounds which have same molecular formula but possess different functional groups are called functional isomers. For example, aldehydes are functional isomers of ketones while alcohols are the functional isomers of the ether. In the given structures, I, II, III, IV represent alcohols and V, VI, VII are ethers. Hence, I and V, I and VI, I and VII, II and V, II and VI, II and VII, III and V, III and VI, III and VII, IV and V, IV and VI, IV and VII are functional group isomers.

Note: Consider structures I to VII and answer the question Identify the pairs of compounds that represents position isomerism.

In position isomerism, two or more compounds differ in the position of functional group, substituent or multiple bonds but molecular formula is identical. In the given structures, I and II, III and IV, and VI and VII are position isomers. I. CH 3 - CH 2 - CH 2 - CH 2 - OH and II. CH 3 — CH 2 — CH ( OH ) — CH 3 are position isomers. III. CH 3 — C ( CH 3 ) ( OH ) - CH 3 and IV. CH 3 — CH ( CH 3 ) — CH 2 — OH are position isomers. VI. CH 3 — O — CH 2 — CH 2 — CH 3 and VII. CH 3 — O — CH ( CH 3 ) — CH 3 are position isomers.

Note: Consider structures I to VII and answer the question Identify the pairs of compounds that represents chain isomerism.

When two or more compounds have similar molecular formula, same functional groups but different carbon skeletons, these are referred to as chain isomers and the phenomenon is termed as chain isomerism. I and III, I and IV, II and III, II and IV are chain isomerism.