An unknown organic hydrocarbon, identified strictly as an alkane, exhibits clear optical activity. W — Isomerism and Stereochemistry Chemistry Question

💡 Solution & Explanation

For an acyclic alkane to be chiral, it must contain a chiral stereocenter. The smallest possible groups to attach to a central chiral $sp^3$ carbon without duplicating any are Hydrogen (0 carbons), Methyl (1 carbon), Ethyl (2 carbons), and Propyl (3 carbons). Adding the central chiral carbon itself gives a minimum total of $0 + 1 + 2 + 3 + 1 = 7$ carbon atoms (e.g., 3-methylhexane).