2025 CCHY Prelim P2 QP

This document consists of 22 printed pages, INCLUDING the cover page and 1 blank page. [Turn over Ex 2025 Preliminary Examination Secondary Four Express CANDIDATE NAME CLASS INDEX NUMBER CHEMISTRY 6092/02 Paper 2 19 August 2025 Candidates answer on the Question Paper. Additional Materials: NIL 1 hour 45 minutes READ THESE INSTRUCTIONS FIRST Write your name, class and index number in the spaces at the top of this page. Write in dark blue or black pen. You are to use a soft pencil for any diagrams or graphs. Do not use staples, paper clips, glue, correction fluid or correction tape. 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 22. The use of an approved scientific calculator is expected, where appropriate. For Examiner’s Use Section A Section B Total O CHUNG CHENG HIGH SCHOOL (YISHUN)

2 CCHY 2025 6092/02/Sec4Express/Prelim/2025 BLANK PAGE

3 CCHY 2025 6092/02/Sec4Express/Prelim/2025 Section A Answer all questions. 1 Fig. 1.1 shows part of the Periodic Table. Fig. 1.1 Select elements from Fig. 1.1 to answer the following questions. You may use each element once, more than once or not at all. Write down the symbol for an element which (a) forms a stable ion by losing three electrons, ………………………………………………………………………………….……….[1] (b) exists as diatomic molecules, ………………………………………………………………………………….……….[1] (c) forms an ion which gives a red-brown precipitate on additon of aqueous ammonia, ………………………………………………………………………………….……….[1] (d) has chemical properties similar to those of magnesium, ………………………………………………………………………………….……….[1] (e) has a giant covalent structure, ………………………………………………………………………………….……….[1] (f) reacts with sodium to form an ionic compound with Mr less than 70. ………………………………………………………………………………….……….[1] [Total: 6]

4 CCHY 2025 6092/02/Sec4Express/Prelim/2025 2 Fig. 2.1 shows the label on a bottled mineral water. ions present mol/dm3 Ca2+ 20 K+ 30 Na+ 145 H+ 185 OH- 225 HCO3- 289 SO42- 410 dry residue at 180oC 210 mol/dm3 Fig. 2.1 (a) Suggest whether the bottled mineral water is acidic, alkaline or neutral. Explain your reasoning. …………………………………………………………………………………………….. …………………………………………………………………………………………..[2] (b) State the name and formulae of two salts that could be present in the bottled mineral water. name of salt formula of salt salt 1 salt 2 [2] (c) Describe how the dry residue is obtained from the bottled min