PLMGS 2026 Chem Prelim P2 QP

[Turn over CENTRE NUMBER S INDEX NUMBER CHEMISTRY (G3) 6092/02 Paper 2 19 August 2026 1 hour 45 minutes Candidates answer on the Question Paper. No Additional Materials are required. READ THESE INSTRUCTIONS FIRST Write your name and index number on all the work you hand in. Write in dark blue or black pen. You may use a soft 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. Indicate the question number in the grid 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 2. The use of an approved scientific calculator is expected, where appropriate. This document consists of 22 printed pages. CANDIDATE NAME ( ) CLASS TG For Examiner’s Use Section A / 70 Section B Qn _____ / 10 Total / 80 Paya Lebar Methodist Girls’ School (Secondary) Preliminary Examination 2026 Secondary 4 Express Secondary 4 Express / G3

2 The Periodic Table of Elements Group 1 2 13 14 15 16 17 18 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 3 4 5 6 7 8 9 10 11 12 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 – 113 Nh nihonium – 114 Fl flerovium – 115 Mc moscovium – 116 Lv livermorium – 117 Ts tennessine – 118 Og oganesson – 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 – The volume of one mole of any gas is 24 dm3 at room temperature and pressure (r.t.p.). The Avogadro constant, L = 6.02 x 1023 mol-1.

3 Section A [70 marks] Answer all questions. 1. Use the list of substances to answer the questions. barium carbonate barium nitrate calcium sulfate calcium oxide magnesium nitrate magnesium oxide potassium chloride potassium hydroxide hydrochloric acid carbonic acid sulfuric acid Each substance may be used once, more than once or not at all. (a) Which substance reacts with nitric acid to produce pure potassium nitrate? .……………………………………………………………………………………………… [1] (b) Which two substances can be used to prepare pure barium sulfate? .……………………………………… and ………………………………………………… [1] (c) Which two substances can be used to prepare pure magnesium chloride? .…………………………………… and excess .…….…………………………………… [1] (d) Which substance causes rain to have a pH of 4.5? .……………………………………………………………………………………………… [1] (e) Which substance can be added to soil to neutralise the harmful effect of acid rain? .……………………………………………………………………………………………… [1] [total: 5] [Turn Over

4 2. Tin is a metal that forms both ionic and covalent compounds. (a) Tin(IV) oxide, SnO2, is ionically bonded and exists an amphoteric oxide. SnO2 reacts with aqueous sodium hydroxide, NaOH, to form a sodium salt and water only. The sodium salt contains a negative ion with the formula SnO32−. (i) State the meaning of the term amphoteric. .…………………………………………………………………………………………. .……………………………………………………………………………………… [1] (ii) Write the balanced chemical equation, with state symbols, for the reaction between SnO2 and NaOH. .……………………………………………………………………………………… [2] (iii) The relative formula mass, Mr, of SnO 2 is 151. Calculate the percentage by mass of tin in SnO2. percentage by mass of tin in SnO2 = …………………………… % [1]

5 (b) Tin(IV) chloride, SnC l4, is covalently bonded. A tin atom has four outer shell electrons. Complete the dot-and-cross diagram in Fig. 2.1 for a molecule of SnCl4. Show the outer shell electrons only. Fig. 2.1 [2] (c) The melting points of SnO2 and SnCl4, are shown in Table 2.1. Table 2.1 melting point / °C SnO2 1630 SnCl4 − 34 Explain, in terms of structure and bonding, why SnCl4 has a much lower melting point than SnO2. …....…………………………………………………………………………………………. …....…………………………………………………………………………………………. …....…………………………………………………………………………………………. …....…………………………………………………………………………………………. …....…………………………………………………………………………………………. …...……………………………………………………………………………………… [3] [total: 9] [Turn Over

6 3. Four elements, W, X, Y and Z, from Period 3 of the Periodic Table were investigated. Table 3.1 shows some of the properties of these four elements. Table 3.1 Element W X Y Z Atomic radius (pm) 186 160 110 99 First ionisation energy (kJ/mol) 496 738 1012 1252 Electrical conductivity Good Good Poor Poor (a) First ionisation energy is the energy required to remove the outermost electron from a neutral atom in its gaseous state. Describe and explain the relationship between atomic radius and first ionisation energy. …....…………………………………………………………………………………………. …....…………………………………………………………………