ACSI 2022 Promo Paper 1 questions

1 Anglo-Chinese School (Independent) Year 5 Promotional Examination 2022 INTERNATIONAL BACCALAUREATE DIPLOMA PROGRAMME CHEMISTRY HIGHER LEVEL PAPER 1 Monday 12th September 2022 1 hour Additional materials: Multiple choice answer sheet Soft clean eraser Soft pencil (type 2B recommended) INSTRUCTIONS TO CANDIDATES Do not open this booklet until you are told to do so. Shade your Candidate number on the multiple choice answer sheet provided. There are forty questions in this paper. Answer all the 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 multiple choice answer sheet. INFORMATION FOR CANDIDATES Each correct answer will score one mark. A mark will not be deducted for a wrong answer. Any rough working should be done in this booklet. A copy of the periodic table is provided for reference on Page 2 of the examination paper. Calculators are not allowed to be used in this paper. This question paper consists of 19 printed pages, including the cover page.

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3 1. What is the mass of methane (CH4) that contains 4.80  1023 atoms of hydrogen? Avogadro's constant, NA: 6.02 x 1023 mol–1 A. 2.4 g B. 3.2 g C. 12.8 g D. 13.3 g 2. 20 cm3 of a gaseous hydrocarbon was burnt in 150 cm3 of oxygen. After cooling to room temperature, the residual gaseous products occupied a volume of 110 cm3. The gas was then bubbled through aqueous calcium hydroxide, and it was reduced to 30 cm3. What is the molecular formula of the hydrocarbon? A. C3H6 B. C3H8 C. C4H8 D. C4H16 3. Which element undergoes reduction in the following reaction? (NH4)2Cr2O7 (s) → N2 (g) + 4H2O (l) + Cr2O3 (s) A. Cr B. H C. N D. O

4 4. What is the coefficient for H+ when the following equation is balanced using the smallest possible whole numbers? ____ClO‒ + ____I‒ + ____H+ → ____Cl– + ____I2 + ____H2O A. 1 B. 2 C. 4 D. 5 5. Which graph correctly describes the behaviour of a fixed mass of an ideal gas? (T is measured in K.) I II III A. I and II only B. I and III only C. II and III only D. I, II and III

5 6. Flask X contains 1 dm3 of helium at 2.00 x 103 Pa and flask Y contains 2 dm3 of neon at 1.00 x 103 Pa. The flasks are later connected at a constant temperature, what is the final pressure? A. 1.33  103 Pa B. 1.50  103 Pa C. 1.67  103 Pa D. 2.00  103 Pa 7. Which equation represents a reaction that occurs under standard conditions? A. 2 LiBr (aq) + I2 (aq) → 2 LiI (aq) + Br2 (aq) B. 2 KF (aq) + Cl2 (aq) → 2 KCl (aq) + F2 (aq) C. 2 LiCl (aq) + I2 (aq) → 2 LiI (aq) + Cl2 (aq) D. 2KBr (aq) + Cl2 (aq) → 2 KCl (aq) + Br2 (aq) 8. Which combination of statements about the oxides of period 3 elements is correct? State at room temperature Electrical conductivity in molten state Na2O Al2O3 P4O10 Na2O Al2O3 P4O10 A. solid solid gas good good good B. solid solid solid good good poor C. solid liquid liquid good poor poor D. solid solid solid poor poor good Helium 1dm3 Neon 2dm3

6 9. Which statements about reactivity are correct? I. Potassium reacts more vigorously than sodium with chlorine. II. Lithium reacts more vigorously than potassium with water. III. Fluorine reacts more vigorously than bromine with potassium iodide solution. A. I and II only B. I and III only C. II and III only D. I, II and III 10. Which ion is colourless? A. [Sc(H2O)6]3+ B. [Cr(H2O)6]3+ C. [Fe(H2O)6]3+ D. [Fe(CN)6]3− 11. Which statements are correct for the complex ion [Cu(EDTA)]2−? I. The oxidation number of Cu in the complex ion is +2. II. The coordination number of the Cu ion is 6. III. The shape of the complex ion is linear. A. I and II only B. I and III only C. II and III only D. I, II and III

7 12. Which properties of transition elements are not shown by s -block elements such as calcium? I. Transition metal ions have variable oxidation states. II. Transition metal ions can act as oxidising agents in aqueous solution. III. Transition metals can be used as catalysts for industrial processes. A. I and II only B. I and III only C. II and III only D. I, II and III 13. Which combination correctly describes the geometry of XeF3+? Electron domain geometry around Xe Molecular geometry around Xe A. Octahedral T-shape B. Trigonal bipyramidal Square planar C. Octahedral Square planar D. Trigonal bipyramidal T-shape 14. Which of the following pairs of molecules are both planar and polar? A. BeCl2 and NO2 B. SiO2 and CO2 C. BF3 and NH3 D. ClF3 and SO2

8 15. Molecular dimerization can be described as the process in which two identical molecules combine to give a single product. Some examples of dimers include Al2Cl6 and N2O4. Which of the following descriptions about the two dimers is incorrect? A. Al2Cl6 is a planar molecule. B. The nitrogen–oxygen bond angle is 120o. C. Al2Cl6 is formed by two dative bonds between Al and Cl. D. N2O4 is a non-polar molecule. 16. Trimethoprim (TMP) is used for the treatment and prevention of urinary tract infection. It has the following structure. In which sequence is the bond angles quoted in decreasing order? A. x > y > w > z B. x > y > z > w C. y > w > z > x D. y > z > w > x

9 17. The standard enthalpy changes for two reactions are given below. 4Ag (s) + O2 (g) → 2Ag2O (s) H = −62 kJ C (s) + O2 (g) → CO2 (g) H = −394 kJ What is the standard enthalpy change in kJ when 108 g of silver is obtained from the reduction of silver(I) oxide? 2Ag2O (s) + C (s) → 4Ag (s) + CO2 (g) A. –332 B. –83 C. –456 D. −114 18. Four reactions of the type shown are studied at the same temperature. X (g) + Y (g) → Z (g) Which is the correct reaction pathway diagram for the reaction that would proceed most rapidly and with good yield? A. B. C. D.

10 19. The standard enthalpy change for this reaction is +142 kJ mol−1. 3 2O2 (g) → O3 (g) What is the bond enthalpy of the oxygen-oxygen bond in O3, given that the bond enthalpy of O=O is 498 kJ mol−1? A. 498 – (142) 2 B. 498 + (142) 3 C. 3 2  498 – (142) 2 D. 3 2  498 – (142) 3 20. Which processes are more exothermic for Mg than that of Ca? I. X (g) → X (s) II. X2+ (g) + O2− (g) → XO (s) III. X2+ (g) → X2+ (aq) A. I and II only B. I and III only C. II and III only D. I, II and III 21. Hand warmers, when activated, generate their warmth by the spontaneous crystallisation of sodium ethanoate from a supersaturated solution. Which row describes the entropy changes involved? ∆Ssystem ∆Ssurroundings ∆Suniverse A. decrease decrease decrease B. decrease increase increase C. increase decrease increase D. increase increase decrease