YCKSS Sc(Chem) Prelim

BP - 329 Name: lndex Number: Class: YIO CHU KANG SECONDARY SCHOOL O.LEVEL PRELIMINARY EXAMINATION 2024 SECONDARY FOUR EXPRESS scrENcE (PHYSTCS / CHEMTSTRY) Paper 1 Additional Material: Optical Answer Sheet (OAS) 5086/01 t hour 23 August 2024 (Friday) READ THESE INSTRUCTIONS FIRST Write in soft pencil on the OAS. Do not use staples, paper clips, glue or correction fluid. Write your name, index number and class on the OAS in the spaces provided. There are fofi questions on this paper. Answer all questions. For each question there are four possible answers A, B, c and D. Choose the one you consider conect and record your choice in soft pencil on the separate OAS Read the instructions on the OAS very carefully. Each conect answer will score one mark. A mark will not be deducted for a wrong answer. Any rough working should be done in this question paper. The use of an approved scientific calculator is expected, where appropriate. The colours of some common metal hydroxides are given on page 8. A copy of the Periodic Table is printed on page 9. For Examiner's Use 40 Setters: Mdm Toh Lee Wah This document consists of 9 printed pages. I

BP - 331 1 An acidic gas T is denser than air and insoluble in water. Which method(s) can be used to collect the gas? 1 32 A B c D A B c D 2 only 3 only 1and2 2and3 2 Bromine is a liquid at 20 'C. What is the melting point and boiling point for bromine? melting poinv 'C boiling poinY 'C A B c D -22 -8 -7 25 -3 -33 59 103 3 What changes occur when a gas at 200 "C becomes a solid at -5'C? 4 What ions are present in iron([l) sulfate, Fe2(SO4)3? Fe2' and SO+2- Fe2* and SO+3- Fe3* and SOr2- Fe3' and SOr} separation of Particles energy of particles attractive forces between particles A B c D decreases decreases increases increases decreases increases decreases increases increases decreases increases decreases I m I

BP- 332 5 The diagram shows the molecule ethyl propanoate. o // cH3-cH2 - c \ o-GH2-CHs How many bonding pairs of electrons are there in the molecule? A B c D A B c D 7 16 17 20 6 Aqueous solution R is gradually added to aqueous solution S. The changes in pH are shown on the graph. pH 11 13 12 1l r0 9 I 7 E I 3 2 1 0 10 rt 20 25 30 35 10 45 50 volume of R added/ cm3 What are R and S? R S A B c D aqueous ammonia ethanoic acid hydrochloric acid sodium hydroxide ethanoic acid sodium hydroxide aqueous ammonia hydrochloric acid 7 which substance does not produce coppe([) sulfate when added to dilute sulfuric acid? copper copper(tr) carbonate copper(tr) hydroxide coppe(Il) oxide 0 5 I

BP - 333 8 Which element contains the least number of atoms in 1 g? carbon iodine iron orygen I A B c D Aqueous sodium hydroxide and aqueous ammonia were added separately to two different aqueous solutions each containing the same metatlic ion. ln both cases, a white precipitate was formed which dissolved when excess sodium hydroxide or aqueous ammonia was added. What is the ion? Ca2' Cu2* K- Zn2t {O A simplified version of the Periodic Ta