Copy of PLMGSS 2024 4E Chem P2 QP

1 CANDIDATE NAME CLASS CLASS INDEX NUMBER CENTRE NUMBER S INDEX NUMBER CHEMISTRY 6092/02 Paper 2 14 August 2024 1 hour 45 minutes Candidates answer on the Question Paper. No Additional Materials are required. READ THESE INSTRUCTIONS FIRST Write your name and index number on all the work you hand in. Write in dark blue or black pen. You may use a soft pencil for any diagrams or graphs. Do not use staples, paper clips, glue or correction fluid. Section A Answer all questions. Write your answers in the spaces provided. Section B Answer one question. Write your answers in the spaces provided. The number of marks is given in brackets [ ] at the end of each question or part question. A copy of the Periodic Table is printed on page 27. The use of an approved scientific calculator is expected, where appropriate. For Examiner’s Use Section A /70 Section B /10 Total /80 Paya Lebar Methodist Girls’ School (Secondary) Preliminary Examination 2024 Secondary 4 Express / G3 This document consists of 27 printed pages. [Turn Over

2 Section A Answer all questions. 1. Barium hydroxide, Ba(OH)2 is a strong base. Fig 1.1 shows a reaction scheme involving barium hydroxide. Fig. 1.1 (a) State what is observed in reaction 1. ……………………………………………………………………………………………… [1] (b) Suggest a reactant for reaction 2. ……………………………………………………………………………………………… [1] (c) Identify A. ……………………………………………………………………………………………… [1] (d) Ba(OH)2 is made by reaction of Ba with water. Write a balanced chemical equation for this reaction. ……………………………………………………………………………………………… [1]

3 (e) The mineral barytocalcite contains both BaCO3 and CaCO3. Both compounds decompose on heating. (i) Using your knowledge on the reactivity of metals, predict which compound decomposes first when barytocalcite is heated. Explain your answer. ………………………………………………………………………………………….. ………………………………………………………………………………………….. …………………………………………………………………………………………. …………………………………………………………………………………………. …………………………………………………………………………………...… [2] (ii) Construct an equation for the complete thermal decomposition of barium carbonate. ……………………………………………………………………………………… [1] [Total: 7] 2. The elements phosphorus, sulfur and chlorine are elements in Period 3 of the Periodic Table. Table 2.1 shows some properties of these three elements. property P S Cl number of valence electrons 5 6 7 formula of most common ion P3- S2- Cl- Table 2.1 (a) P3-, S2- and Cl- have the same number of electrons. Describe and explain the trend in ionic radius shown by P3-, S2- and Cl-. ………………………………………………………………………………………………… ………………………………………………………………………………………………… ………………………………………………………………………………………………… ……………………………………………………………………………………………… [2] [Turn Over

4 (b) Chlorine forms various ions with