NASS 4NA Science Chemistry P3 P4 and ANS KEY Combined 2023

Name: ........................................................................ Register no: ........... Class: ..... NGEE ANN SECONDARY SCHOOL NA PRELIMINARY EXAMINATION SCIENCE CHEMISTRY 5105/03, 5105/04 17 August 2023 1 h 15 min Additional Materials: Optical Answer Sheet (OAS) Instructions to Candidates Write your name, register number and class at the top of this page. Write in dark blue or black pen. You may use pencil for any diagrams, graphs, tables or rough working. The use of an approved scientific calculator is expected, where appropriate. You may lose marks if you do not show your working or if you do not use appropriate units. If the degree of accuracy is not specified in the question, give the answer to three significant figures. Paper 3 (Multiple Choice Questions) Answer all questions. For each question there are four possible answers A, B, C and D. Choose the one you consider correct and record your choice in the Optical Answer Sheet provided. Paper 4 - Section A Answer all questions. Write your answers in the spaces provided on the question paper. Paper 4 - Section B Answer any two questions. Write your answers in the spaces provided on the question paper. Check by student: _____________________ Date: _________ This document consists of 16 printed pages and 0 blank pages. For Examiner’s Use Section Marks Paper 3 /20 Paper 4 – Section A /14 Paper 4 – Section B /16 Total /50

2 NAS/2023/Preliminary Examination/4NA/Science Chemistry/5105/P3 & P4 The Periodic Table of Elements The volume of one mole of any gas is 24 dm3 at room temperature and pressure (r.t.p.) Group I II III IV V VI VII 0 Key 1 H hydrogen 1 2 He helium 4 3 Li lithium 7 4 Be beryllium 9 proton (atomic) number atomic symbol name relative atomic mass 5 B boron 11 6 C carbon 12 7 N nitrogen 14 8 O oxygen 16 9 F fluorine 19 10 Ne neon 20 11 Na sodium 23 12 Mg magnesium 24 13 Al aluminium 27 14 Si silicon 28 15 P phosphorus 31 16 S sulfur 32 17 Cl chlorine 35.5 18 Ar argon 40 19 K potassium 39 20 Ca calcium 40 21 Sc scandium 45 22 Ti titanium 48 23 V vanadium 51 24 Cr chromium 52 25 Mn manganese 55 26 Fe iron 56 27 Co cobalt 59 28 Ni nickel 59 29 Cu copper 64 30 Zn zinc 65 31 Ga gallium 70 32 Ge germanium 73 33 As arsenic 75 34 Se selenium 79 35 Br bromine 80 36 Kr krypton 84 37 Rb rubidium 85 38 Sr strontium 88 39 Y yttrium 89 40 Zr zirconium 91 41 Nb niobium 93 42 Mo molybdenum 96 43 Tc technetium - 44 Ru ruthenium 101 45 Rh rhodium 103 46 Pd palladium 106 47 Ag silver 108 48 Cd cadmium 112 49 In indium 115 50 Sn tin 119 51 Sb antimony 122 52 Te tellurium 128 53 I iodine 127 54 Xe xenon 131 55 Cs caesium 133 56 Ba barium 137 57 – 71 lanthanoids 72 Hf hafnium 178 73 Ta tantalum 181 74 W tungsten 184 75 Re rhenium 186 76 Os osmium 190 77 Ir iridium 192 78 Pt platinum 195 79 Au gold 197 80 Hg mercury 201 81 Tl thallium 204 82 Pb lead 207 83 Bi bismuth 209 84 Po polonium - 85 At astatine - 86 Rn radon - 87 Fr francium - 88 Ra radium - 89 – 103 actinoids 104 Rf rutherfordium - 105 Db dubnium - 106 Sg seaborgium - 107 Bh bohrium - 108 Hs hassium - 109 Mt meitnerium - 110 Ds darmstadtium - 111 Rg roentgenium - 112 Cn copernicium - 114 Fl flerovium - 116 Lv livermorium - lanthanoids 57 La lanthanum 139 58 Ce cerium 140 59 Pr praseodymium 141 60 Nd neodymium 144 61 Pm promethium - 62 Sm samarium 150 63 Eu europium 152 64 Gd gadolinium 157 65 Tb terbium 159 66 Dy dysprosium 163 67 Ho holmium 165 68 Er erbium 167 69 Tm thulium 169 70 Yb ytterbium 173 71 Lu lutetium 175 actinoids 89 Ac actinium - 90 Th thorium 232 91 Pa protactinium 231 92 U uranium 238 93 Np neptunium - 94 Pu plutonium - 95 Am americium - 96 Cm curium - 97 Bk berkelium - 98 Cf californium - 99 Es einsteinium - 100 Fm fermium - 101 Md mendelevium - 102 No nobelium - 103 Lr lawrencium -

3 NAS/2023/Prelims/4NA/SCIENCE(CHEMISTRY) 5105 Paper 3: Section A: Multiple Choice Questions [20 marks] Record your answers on the separate Optical Answer Sheet (OAS) provided. 1. In the diagrams, each circle represents an atom. Different sized circles represent different atoms. Which diagram represents a mixture? 2. A student wishes to add exactly 11.65 cm3 of acid to exactly 25.0 cm3 of an alkali as part of an experiment. Which apparatus should the student use to measure these volumes? acid alkali A pipette burette B burette measuring cylinder C burette pipette D measuring cylinder pipette 3. Which of the following contains mixtures only? A air and sugar B calcium hydroxide and water C carbon monoxide and air D sea water and brass 4. What happens when ice melts? A Covalent bonds in a giant lattice are broken. B Electrons are released from atoms. C Intermolecular forces of attraction are overcome. D Molecules are separated into ions.

4 NAS/2023/Prelims/4NA/SCIENCE(CHEMISTRY) 5105 5. Which diagram shows the outer electron arrangement in calcium fluoride? A an electron from calcium an electron from fluorine B C D 6. An excess of calcium hydroxide is added to an acidic soil. What happens to the pH of the soil? change in pH final pH A decrease 5 B decrease 12 C increase 7 D increase 12 7. Aqueous solution X is added to aqueous ammonium chloride. The mixture is heated and ammonia gas is given off. What is X? A ammonium sulfate B hydrochloric acid C sodium chloride D sodium hydroxide

5 NAS/2023/Prelims/4NA/SCIENCE(CHEMISTRY) 5105 8. Which one of the following is an amphoteric oxide? A carbon dioxide B copper(II) oxide C sulfur dioxide D aluminium oxide 9. An atom of element R has an electronic structure of 2,8,6. The positions in the Periodic Table of four elements are shown. Which element will have properties most similar to R? A B C D 10. Three elements each have two valence electrons. Which statement about the elements is correct? A They are all metallic and belong to the same group of the Periodic Table. B They are all metallic but belong to different groups of the Periodic Table. C They are all non-metallic and belong to the same group of the Periodic Table. D They are all non-metallic but belong to different groups of the Periodic Table. 11. The relative atomic mass of chlorine is 35.5. What is the mass of 1.5 moles of chlorine gas? A 35.5 g B 71.0 g C 106.5 g D 142 g 12. What is the relative formula mass, Mr, of ammonium sulfate, (NH4)2SO4? A 70 B 114 C 132 D 216

6 NAS/2023/Prelims/4NA/SCIENCE(CHEMISTRY) 5105 13. Pieces of silver, iron and calcium, of the same size and shape, are added to dilute hydrochloric acid. The diagram shows the results. test-tube 1 test-tube 2 test-tube 3 Which metal was placed in each test-tube? test-tube 1 test-tube 2 test-tube 3 A iron silver calcium B iron calcium silver C calcium silver iron D silver iron calcium 14. Which statement about recycling of metals is not correct? A Recycling enables the finite metal resources to last longer. B Recycling saves the cost of extracting new metals from ores. C Recycling reduces rubbish at l