FHSS Chem Prelim P2

Candidate Name: Class: Index No.: FUHUA SECONDARY SCHOOL Secondary Four Express PRELIMINARY EXAMINATION 2025 4E Fuhua Secondary School Fuhua Secondary School Fuhua Secondary School Fuhua Secondary School Fuhua Secondary School Fuhua Seco ndary School Fuhua Secondary School Fuhua Secondary School Fuhua Secondary School Fuhua Secondary School Fuhua Secondary School Fuhua Seco ndary School Fuhua Secondary School Fuhua Secondary School Fuhua Secondary School Fuhua Secondary School Fuhua Secondary School Fuhua Seco ndary School Fuhua Secondary School Fuhua Secondary School Fuhua Secondary School Fuhua Secondary School Fuhua Secondary School Fuhua Seco ndary School Fuhua Secondary School Fuhua Secondary School Fuhua Secondary School Fuhua Secondary School Fuhua Secondary School Fuhua Seco ndary School CHEMISTRY 6092/2 Paper 2 DATE 22 August 2025 TIME 1045 - 1230 DURATION 1 hour 45 minutes READ THESE INSTRUCTIONS FIRST Write your name, class and index number on all the work you hand in. Write in dark blue or black pen. You may use an HB 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 24. The use of an approved scientific calculator is expected, where appropriate. PARENT’S SIGNATURE FOR EXAMINER’S USE Section A Section B Total /70 /10 /80 This document consists of 23 printed pages and 1 blank page.

2 Section A Answer all questions. 1 Fig. 1.1 shows the electron arrangement of six elements from Period 3 of the Periodic Table. The elements are represented by the letters, A, B, C, D, E and F. Each diagram shows outer electrons only. A B C D E F Fig. 1.1 (a) Which elements are reducing agents? [1] (b) Which elements form oxides that react with aqueous sodium hydroxide only? [1] (c) Which element exists as a giant network of atoms that are covalently bonded? [1] (d) Draw a ‘dot-and-cross’ diagram to show the bonding of the compound formed between element B and D. [2] [Total: 5]

3 2 Sulfuric acid, widely used in the production of detergents and fertilisers, is manufactured on an industrial scale via the Contact Process. The process involves the following key reactions as shown in Table 2.1. Table 2.1 stage reaction conditions 1 S (s) + O2 (g) → SO2 (g) ΔH = - 297 kJ/mol 2 2SO2 (g) + O2 (g) ⇌ 2SO3 (g) 450 °C 1- 2 atm V2O5 as catalyst H = - 196 kJ/mol 3 SO3 (g) + H2SO4 (l) → H2S2O7 (l) Heat produced varies. 4 H2S2O7 (l) + H2O (l) → 2H2SO4 (aq) Heat produced varies. (a) A student made the following comment.