NEET Chemistry Question (2026) — Solution

Step-by-step solution

Metamerism is a type of structural isomerism where isomers have the same molecular formula but differ in the nature of the alkyl groups attached to the same polyvalent functional group (such as - O -, - S -, - NH -, - CO -). In option (1), CH _3 CH _2 CH _2 OH and CH _3- CH(OH) - CH _3 are position isomers because the position of the - OH group differs. In option (2), CH _3 CH _2 CH _2 CH _2 CH _3 and ( CH _3)_2 CHCH _2 CH _3 are chain isomers because the carbon skeleton differs. In option (3), H _3 C - CO - CH _3 and H _3 C - CH _2- CHO are functional isomers because they have different functional groups (ketone and aldehyde). In option (4), CH _3 OCH _2 CH _2 CH _3 (methoxypropane) and CH _3 CH _2 OCH _2 CH _3 (ethoxyethane) have the same polyvalent functional group (- O -) but different alkyl groups attached to it (methyl and propyl versus two ethyl groups). Thus, they are metamers. Answer: CH _3 OCH _2 CH _2 CH _3 and CH _3 CH _2 OCH _2 CH _3