MHT CET Chemistry Question (2026) — Solution

Step-by-step solution

Methanal is H-CHO. The aldehydic group (-CHO) is attached to a hydrogen atom, not to any carbon atom. Therefore, it is not attached to any sp^3 hybridized carbon atom. Ethanal is CH_3-CHO. The -CHO group is attached to a methyl group, which contains an sp^3 hybridized carbon atom. 2-Methylpropanal is (CH_3)_2CH-CHO. The -CHO group is attached to a CH group, which is an sp^3 hybridized carbon atom. Propanal is CH_3-CH_2-CHO. The -CHO group is attached to a CH_2 group, which is an sp^3 hybridized carbon atom. Thus, methanal is the only aldehyde among the given options where the aldehydic group is not attached to an sp^3 hybridized carbon atom.