Question

What type of isomerism exists between the following pairs of compounds?
(i) Pentan-1-ol and 3-Methylbutan-1-ol
(ii) Ethanol and Dimethyl ether
(iii) Butan-1-ol and Butan-2-ol

• A. (i) Chain isomerism (ii) Functional isomerism (iii) Position isomerism
• B. (i) Functional isomerism (ii) Chain isomerism (iii) Position isomerism
• C. (i) position isomerism (ii) Chain isomerism (Iii) Functional isomerism
• D. (i) Chain isomerism (ii) Position isomerism (iii) Functional isomerism

Answer 1

The correct option is A (i) Chain isomerism (ii) Functional isomerism (iii) Position isomerism

(i) Pentan-1-ol and 3-Methylbutan-1-ol: Both have the same number of carbons but the length of the parent carbon chain is different. Thus the pair shows chain isomerism.

(ii) Ethanol and Dimethyl ether: Both have the same number of atoms but form two classes of functional groups of organic compounds i.e. alcohol and ether, respectively. Thus they show functional isomerism.

(iii) Butan-1-ol and Butan-2-ol: The position of the functional group in the parent chain is different. Thus shows position isomerism.