See image — Hydrocarbons Chemistry Question

💡 Solution & Explanation

Concept: Chlorine content (mass percent) is calculated as (number of Cl atoms × 35.5) / molecular weight × 100. Step 1: Identify each compound and its molecular formula. - Pyrene: C16H10 — contains NO chlorine atoms. Chlorine content = 0%. - DDT: C14H9Cl5 — molecular weight = 14(12) + 9(1) + 5(35.5) = 168 + 9 + 177.5 = 354.5. Chlorine content = 177.5/354.5 × 100 ≈ 50.07%. - Chloral: CCl3CHO (C2H1Cl3O) — molecular weight = 2(12) + 1(1) + 3(35.5) + 16 = 24 + 1 + 106.5 + 16 = 147.5. Chlorine content = 106.5/147.5 × 100 ≈ 72.2%. - Gammaxene (BHC/Lindane): C6H6Cl6 — molecular weight = 6(12) + 6(1) + 6(35.5) = 72 + 6 + 213 = 291. Chlorine content = 213/291 × 100 ≈ 73.2%. Step 2: Compare chlorine percentages. - Pyrene: 0% - DDT: ~50.07% - Chloral: ~72.2% - Gammaxene: ~73.2% Step 3: Gammaxene (C6H6Cl6) has the highest chlorine content at approximately 73.2%. Why other options fail: - Pyrene has no chlorine at all. - DDT has only ~50% chlorine content. - Chloral has ~72.2% chlorine, which is close but slightly less than Gammaxene. Therefore, the correct answer is A.