See image — IUPAC and Nomenclature Chemistry Question

💡 Solution & Explanation

Step 1: Analyze structure (a). Structure (a) shows a cyclohexane ring where C1 has two chlorine atoms (gem-dichloro) and C2 has one bromine atom. This corresponds to 2-bromo-1,1-dichloro cyclohexane, which is option (q). So a → q. Step 2: Analyze structure (b). Structure (b) shows a cyclohexane ring with a butyl chain (four-carbon chain) on one carbon and a methyl group on another carbon. The substituents appear to be at C1 and C4 positions (para to each other). This corresponds to 1-butyl-4-methyl cyclohexane, which is option (p). So b → p. Step 3: Analyze structure (c). Structure (c) shows a cyclohexane ring where C1 has a COOEt (ethyl ester) group and C2 has a CHO (aldehyde/formyl) group. The IUPAC name would be ethyl 2-formylcyclohexane-1-carboxylate, commonly called Ethyl-2-formyl cyclohexane carboxylate, which is option (s). So c → s. Step 4: Analyze structure (d). Structure (d) shows a cyclohexane ring where C1 bears one Br and two Cl atoms (i.e., 1-bromo-1,1-dichloro pattern) — wait, re-examining: the structure shows Br and Cl on C1 and another Cl on C2 (adjacent carbon). This corresponds to 1-Bromo-1,2-dichloro cyclohexane — C1 has Br and one Cl, C2 has one Cl. This matches option (r). So d → r. Verification: - (a) gem-dichloro at C1 + Br at C2 = 2-bromo-1,1-dichlorocyclohexane = (q) ✓ - (b) butyl at C1 + methyl at C4 = 1-butyl-4-methylcyclohexane = (p) ✓ - (c) COOEt at C1 + CHO at C2 = Ethyl-2-formylcyclohexane carboxylate = (s) ✓ - (d) Br and Cl at C1 + Cl at C2 = 1-Bromo-1,2-dichlorocyclohexane = (r) ✓ Therefore, the correct answer is {"a": "q", "b": "p", "c": "s", "d": "r"}.