Determine the total number of open-chain (acyclic) structural isomers possible for a hydrocarbon wit — Hydrocarbons Chemistry Question

💡 Solution & Explanation

A hydrocarbon with formula $C_4H_6$ has a Degree of Unsaturation (DU) of 2. For open-chain structures, this implies either one triple bond or two double bonds. The possible alkynes are but-1-yne and but-2-yne (2 isomers). The possible alkadienes are buta-1,3-diene (conjugated) and buta-1,2-diene (cumulated/allene) (2 isomers). Total = $2 + 2 = 4$ acyclic structural isomers.