Pasir-Ris-Secondary-Sec-3-Science-Chemistry-EOY-2021

Pasir Ris Secondary Schoo! Name Class Register Number SECONDARY 3 EXPRESS END OF YEAR EXAMINATION 2021 sclENcE (cHEMISTRY) Paper 1 Multiple Choice Wednesday 0800 - 0930 Candidates answer on the Question Paper No Additional Materials are required. 13 oci2021 Papers 'l and 2: t hour 30 minutes 70 marks READ THESE INSTRUCTIONS FIRST Write your name, class and register number on all the work you hand in. Write in dark blue or black pen. Do not use staples, paper clips, glue or conection fluid. There are ten 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 the boxes provided on page /t 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 paper. A copy of the Periodic Table is printed on page 12 of Paper 2. The use of an approved scientific calculator is expected, where appropriate. This document consists of 4 printed pages, including the cover page Setter: Ms Chua Wei Tian PartnerlnLearning 147 flurn over BP- 148 @ You are advised to spend no more than 15 minutes on Paper'1. You may proceed to answer Paper 2 as soon as you have completed Paper 1. At the end of the examination, submit your answers to Paper 1 and Paper 2 separately.

,| pRss-2oz r-Eov-s3 E -s c t (c H E B-P1' 1 49 Rock salt is a mixture of sand and sodium chloride. Sodium chloride is soluble in water but not in alcohol. Sand is insoluble in both water and alcohol. What is required to separate sand from the sodium chloride? 1 alcohol 2 filter paper 3 fractionating column 4 water B D A c 1and3 2and3 1and4 2and4 2 2.OO g of powdered calcium carbonate is added to 49.00 cm3 of dilute hydrochloric acid. which apparatus is best used to measure the calcium carbonate and dilute hydrochloric acid? calcium carbonate A B G D beaker beaker mass balance mass balance burette pipetle bu rette pipette Four coloured dyes are separated using chromatography. which chromatogram shows a dye which contains an insoluble component? ABCD baseline 4 Period 3 of the Periodic Table is shown. Na Mg AI Si P S ct Ar Which characteristic of the elements increases from Na to Ar across Period 3? 3 B D A c density non-metallic charac,ter melting point number of electron shells PartnerlnLeaming 148 t tt t t I tt t t t L- t' 2 hydrochloric acid

5 PRss-202r-EoY-s3E-sc(cHEEP' 1 5 0 An element Y reacts with orygen to form an ionic compound with the formula Y2O3. Which group of the Periodic Table is element Y found in? B D A c Group tr Group V Group III Group VII KandM L only H.(aq) + oH-(aq) ---+ Hzo(/) Nat(aq) + OH-(aq) ---r NaOH(aq) 6 Lead(tl) oxide is an amphoteric oxide. Which statement about lead(Il) oxide is conect? It will not react with hydrochloric acid but will react with sodium hydroxide, It will not react with hydrochloric acid or sodium hydroxide. It will react with hydrochloric acid and sodium hydroxide. It will react with hydrochloric acid but not sodium hydroxide. 7 Four different solutions, J, K, L and M, are tested with Universal lndicator. Which solutions are acidic? A B c D A B c D 8 What is the ionic equation for the reaction between dilute nitric acid and dilute sodium hydroxide? B D A c I Which statement about evaporation is false? It occurs only at the boiling point. It occurs only at the surface of the liquid. It occurs slowly. It occurs when a substance converts from the liquid to the gaseous stat6 PartnerlnLeaming 149 solution J K M colour with Universal lndicator green purple orange 3 JandM K only L red A H.(aq) + NO:-(aQ) ---r HNOa(aq) B c Na.(aq) + Noe-(aQ) '-, NaNos(aQ) D

PRss-2,2r-Eo v-s3 u-, ", t" r, F-P,- 1 5 1 1O Which technique can be used to obtain a pure sample of water from sodium chloride solution? B solution A filter paper solution solution containing solid Ansvvers for Paper 1 evaporating dish thermometer solution End of Paper 1 water out water in spot of dye boiling water I I c solid heat D heat H filter paper t distillatefiltrate PartnerlnLeaming 150 =# I = 1 2 3 4 5 6 8 I 't0 4 7

BP- 153 Pasir Ris Secondary School Name Class Register Number SECONDARY 3 EXPRESS END OF YEAR EXAMINATION 2021 scrENcE (GHEMISTRY) Paper 2 Chemistry Wednesday 0800 - 0930 Candidat* answer on the Ouestion Paper- No Addilional Materials are required. 13oct202'.1 Papers I and 2: t hour 30 minutes 70 marks READ THESE INSTRUCTIONS FIRST Write your class, register number and name on all the work you hand in. Write in dark blue or black pen only. You may use a soft pencil for any diagrams or graphs. Do not use staples, paper clips, highlighters, glue or conection fluid. Answer all questions in Section A and two questions in Section B. The use of an approved scientific calculator is expected, wh€re appropriate' ln calculations, you should show all the steps in your working, giving your answer at each stage. You are advised to spend no longer than 15 minutes on Paper 1' You may proceed to answer Paper 2 as soon as you have completed Paper 1' A copy of the Periodic Table is printed on page 12 of Papet 2' At the end of the examination hand in your answers to Paper 'l and Paper 2 separately. The number of marks is given in brackets [ ] at the end of each question or part question' This document consists of 'l For Examino/s Use Section A Section B Total 2 printed pages, PartnerlnLeaming 152 Setter: Ms Chua Wei Tian including the cover Page lTurn over @

BP- 1 54 PRSS_202 r'..EOy_S3E_ SC t (C H E M) _P 2 Section A [40 marks] Answer all the questions in this section. Write your answers in the spaces provided on the question paper. Table 1 .'l substance melting point / 'C boiling point / 'C w -182 -161 x 1'15 445 Y -7 59 z -169 -85 (a) ldentify the substance that exists as a liquid at room temperature and pressure. ...t11 (b) ldentify the substance that exists as a gas at -100'C. t1l (c) Draw, in the box provided in Fig. 1.1, the arrangement of particles in substance X at -10.C. You may use circles to represent the particles. Fig. 1.1 tll(d) Explain, in terms of kinetic particle theory, the change in the anangement and movement of the particles in substance Y as it is heated from -10.C to 10.C. 2 153 I Table 1 .1 shows the melting and boiling points of four substances, W, X, Y and Z. I I PartnerlnLearning

BP- 155 2 PRSS_2027_EOY_S3E_ S C K C H EM ) _P 2 An atom is the smallest particle of an element and can be described as an electrically neutral particle. (a) Explain why an alom is electrically neutral. t1l (b) (l) Complete Table 2.1 to show the number of protons, neutrons and electrons present in atoms of !!tla and ]lNa. Table 2.1 atom number of protons number of neutrons number of electrons 23 11 Na 24 11Na (ii) What is the name given to describe atoms of the same element, such as flNa and liNar 111 (iii) Explain why the chemical properties of llNa and llNa are the same. tzt (iv) Predict one difference in the physical properties of llNa and ]lna. t1l (c) Complete lable 2.2 to identify the charges of particles that have the following numbers of protons, neutrons and eleclrons. f able 2.2 charge of particle number of protons number of neutrons number of electrons 12 12 10 4 5 4 17 20 18 PartnerlnLeaming 154 3 tzt 2+

BP- 156 PRSS_202 r_EOy-S3E_ SC I (CH EM ) -P 2 3 (a) Magnesium chloride has a high melting point and is a conductor of electricity when molten. (i) Name the type of chemical bonding present in magnesium chloride. l1l (ii) Draw a 'dot and cross' diagram to show the arrangement of the outer shell electrons in magnesium chloride in the space provided. [Proton numbers: Mg, 12; C/, 17] I2l (iii) Explain why magnesium chloride is a conductor of electricity when molten but not in the solid state. t2t (b) Chlodne, Clz, has a much lower boiling point than magnesium chloride. Use your knowledge of the bonding in chlorine and magnesium chloride to explain the difference in their boiling points. t2l PartnerlnLearning 1