ACSI 2020 Y3 IP Chemistry FYE

Anglo-Chinese School (Independent) Year 3 Integrated Programme Final Examination 2020 CHEMISTRY PAPER 1 Wednesday 30th September 2020 1 hour Additional material: OTAS answer sheet INSTRUCTIONS TO CANDIDATES Do not open this booklet until you are told to do so. Shade your Candidate Number on the OTAS answer sheet in the spaces provided. 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 soft pencil on the OTAS answer sheet. INFORMATION FOR CANDIDATES There are forty questions in this paper, carrying a total of 40 marks. A copy of the Periodic Table is printed on page 2. Electronic calculators may be used. This booklet consists of 13 printed pages, including this cover page.

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Page 3 of 36 1 Which substance would undergo two changes of state when heated from -20C to 65C? substance melting point / C boiling point / C A. -18 60 B. -24 18 C. -115 56 D. 42 108 2 Which of the following statements about a pure substance during boiling is correct? A. The distance between the particles increases. B. The kinetic energy of the particles increases. C. The size of the particles increases. D. The strength of the forces of attraction between the particles increases. 3 The models and formulae for some molecules are shown below. R2S4 ST Which is the correct model for a molecule of a compound formed between R and T? A. B. C. D.

Page 4 of 36 4 What is the total number of atoms in 36.04 g of water molecules? A. 3.01 x 1023 atoms B. 9.03 x 1023 atoms C. 12.04 x 1023 atoms D. 36.12 x 1023 atoms 5 Which of the following contains the greatest number of ions? A. 10.0 cm3 of 2.5 mol dm-3 of K2CO3 solution B. 20.0 cm3 of 2.0 mol dm-3 of KNO3 solution C. 30.0 cm3 of 1.5 mol dm-3 of K2SO4 solution D. 40.0 cm3 of 1.0 mol dm-3 of K3PO4 solution 6 200 cm 3 of water is added to 50 .0 cm3 of 4 g dm-3 aqueous ammonium nitrate, NH4NO3. What is the new molar concentration of the ammonium nitrate solution? A. 0.0100 mol dm-3 B. 0.0125 mol dm-3 C. 1.28 mol dm-3 D. 1.60 mol dm-3 7 15 cm3 of ethane burns in 35 cm3 of oxygen to form carbon dioxide and water. 2C2H6 (g) + 7O2 (g) ⎯→ 4CO2 (g) + 6H2O (l) What is the total volume of gases remaining after the reaction? All gas volumes are measured at room temperature and pressure. A. 20 cm3 B. 25 cm3 C. 30 cm3 D. 100 cm3

Page 5 of 36 8 0.175 g of a dibasic acid requires 25.0 cm 3 of 0.200 mol dm-3 of aqueous sodium hydroxide to react completely. What is the molar mass of the acid? A. 22.0 g mol-1 B. 35.0 g mol-1 C. 44.0 g mol-1 D. 70.0 g mol-1 9 Dinitrogen tetraoxide, N2O4, is a liquid at room temperature and pressure. The following statements were made about dinitrogen tetraoxide. I. It has a molar volume of 24 dm3 at room temperature and pressure. II. The empirical formula is NO2. III. The percentage mass of nitrogen in the molecule is 30.4%. Which statements are correct? A. I and II B. I and III C. II and III D. I, II and III 10 When nuclear reactions take place, the elements produced are different from the elements that reacted. Nuclear equations, such as the one below, are used to represent the changes that occur. In the equation, the nucleon (mass) number total is constant at 31 and the proton number total is constant at 15 where n0 1 is one neutron. A 13 27 + He2 4 ⎯→ P15 30 + n0 1 In another nuclear reaction, as seen below, nitrogen is reacted with a neutron, n0 1 . An isotope, J, is formed as well as a hydrogen atom. N7 14 + n0 1 ⎯→ J + H1 1 What is isotope J? A. C 12 B. C 14 C. N 14 D. N 15

Page 6 of 36 11 Four electronic configurations are shown below. Three of these belong to atoms of lithium, chlorine and calcium. Which electronic configuration belongs to an atom of another element? A. 1s22s1 B. 1s22s22p3 C. 1s22s22p63s23p5 D. 1s22s22p63s23p64s2 12 What is the condensed electronic configuration for the sulfur atom in its ground state? A. [Mg] 3p4 B. [He] 2s22p63s23p4 C. [Ne] 3s23p4 D. [Ne] 3p6 13 Which statement about the ions 63Cu2+ and 65Cu+ is correct? A. Both ions have the same number of protons. B. Both ions have the same number of electrons. C. Both ions have the same number of neutrons. D. Both ions have the same ionic radius. 14 Element X has a giant metallic structure. Which of the following shows its properties? electrical conductivity physical state of the oxide of X at r.t.p. in the solid state in the liquid state A. solid B. liquid C. gas D. solid

Page 7 of 36 15 Which of the following structures depicts the arrangement of particles in a pure solid metal? A. B. C. D. 16 Which diagram correctly shows the arrangement of ions in solid sodium chloride? A. B. C. D. 17 What happens when potassium bromide melts? A. Covalent bonds in the giant lattice are broken. B. Electrons are released from atoms. C. Electrostatic forces of attraction between ions are overcome. D. Molecules are separated into ions.

Page 8 of 36 18 Which pair will conduct electricity because they both contain mobile ions? A. aqueous copper(II) sulfate and molten sodium chloride B. solid copper metal and aqueous copper(II) sulfate C. solid copper metal and solid graphite D. solid graphite and molten sodium chloride 19 The melting point of calcium oxide is much higher than the melting point of sodium oxide. Which statement explains this? A. Calcium atom has a higher first ionization energy than sodium atom. B. Calcium ion has a bigger charge than sodium ion. C. Calcium ion has greater shielding effect than sodium ion. D. Calcium ion has lesser protons than sodium ion. 20 Which of the following statements provides the best explanation for the solubility of ionic compounds in water? A. Like dissolves like. B. The positive and negative ions are attracted to different regions of the polar water. C. There are delocalised particles in the aqueous state. D. There are positive and negative ions present in the substance. 21 Ethene, C2H4, has very low melting and boiling points. Based on the structure above, this is because of A. weak covalent bonding between atoms in the molecules. B. weak dipole-dipole interactions between molecules. C. weak hydrogen bonding between molecules. D. weak London dispersion forces between molecules. 22 Each of the four molecules below is isolated in the gaseous state. Which species has an atom that does not obey the octet rule? A. BF3 B. CO2 C. C 2 D. NH3

Page 9 of 36 23 The Lewis structure for H3O+ is shown below. What is the shape of H3O+? A. Bent B. Tetrahedral C. Trigonal planar D. Trigonal pyramidal 24 Based on the VSEPR theory, which bond angles correctly correspond to the diagram below? a b c A. 90o 90o 120o B. 109.5o 90o <120o C. <109.5o 109.5o 120o D. 109.5o 109.5o <120o 25 SF6 molecule is shown as below. Which of the following statements are correct about the molecule above? I. The compound would be named sulfur hexafluoride. II. The octet rule is obeyed by all atoms in this Lewis structure. III. The central sulfur atom shows an expanded valence-shell octet observed in some compounds containing Period 3 elements. A. I and II only B. I and III only C. II and III only D. I, II and III c a b

Page 10 of 36 26 Which statement about group 1 elements is correct? A. The density generally decreases down the group. B. The melting point generally increases down the group. C. The oxidizing power increases down the group. D. The reactivity increases down the group. 27 Across a period,