The 2023 G.C.E. (A/L) Chemistry Paper II, held in early 2024 by the Department of Examinations, Sri Lanka. Part A: answer all four structured questions on the paper itself (100 marks each). Parts B and C: answer four essay questions, two from each part (150 marks each). R = 8.314 J K⁻¹ mol⁻¹, Nᴀ = 6.022 × 10²³ mol⁻¹; calculators are not allowed. Answers follow the official marking scheme. The English wording here is from the English-medium paper.