RVHS Prelim P1 QP

1 River Valley High School 9729/01 [Turn over 2018 Preliminary Examinations RIVER VALLEY HIGH SCHOOL YEAR 6 PRELIMINARY EXAMINATION CANDIDATE NAME CLASS 6 CENTRE NUMBER S INDEX NUMBER H2 CHEMISTRY 9729/01 Paper 1 Multiple Choice 20 September 2018 1 hour Additional Materials: Multiple Choice Answer Sheet Data Booklet READ THESE INSTRUCTIONS FIRST Write in soft pencil. Do not use staples, paper clips, highlighters, glue or correction fluid. Write your name, class and index number on the Optical Answer Sheet in the spaces provided. There are thirty 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 correct and record your choice in soft pencil on the Optical Answer Sheet. Read the instructions on the Answer Sheet very carefully. 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. The use of an approved scientific calculator is expected, where appropriate. This document consists of 12 printed pages.

2 River Valley High School 9729/01 [Turn over 2018 Preliminary Examinations For each question there are four possible answers, A, B, C and D. Choose the one you consider to be correct. 2 Sodium thiosulfate (Na 2S2O3) is used in the textile indu stry to remove an excess of chlorine from bleaching processes by reducing it to chloride ions. If 10 cm 3 of 0.20 mol dm −3 of sodium thiosu lfate requires 192 cm 3 of chlorine for complete reaction at r.t.p., which of the fo llowing is a possible fo rmula of the sulfur- containing product? A S B SO2 C HSO4− D H2S 3 Which of the following ions would undergo the smallest deflection in an electric field? A 16O2+ B 16O18O+ C 16O18O2+ D 18O2+ 4 The table below shows the fourth ionisation energies of five consecutive elements in the Periodic Table. Element V W X Y Z Fourth ionisation energy / kJ mol−1 10450 11710 4350 5030 4580 What is the formula of the bromide of V? A VBr B VBr2 C VBr3 D VBr5 1 A mixture of argon and another gas is commonl y used during welding. At s.t.p, the density of the gaseous mixture is 1.82 g dm−3. What is the identity of the other gas in the mixture? [Density of argon = 1.78 g dm−3 at s.t.p.] A neon B nitrogen C oxygen D carbon dioxide

3 River Valley High School 9729/01 [Turn over 2018 Preliminary Examinations 5 Two identical bulbs at the same temperature contain ideal gases P and Q separately. The density of gas P is half that of gas Q while the molecular mass of gas P is twice that of gas Q. What is the ratio of the pressure of gas P to that of gas Q? A 1 : 1 B 1 : 2 C 1 : 4 D 2 : 1 6 The auto-ionisation of bromine trifluoride is represented by the equation: 2BrF3 ⇌ BrF2+ + BrF4− Which of the following statements is correct? A BrF3 is planar while BrF4− is non-planar. B BrF2+ is linear while BrF4− is tetrahedral in shape. C The F−Br−F bond angle in BrF3 is smaller than that in BrF2+. D There are more lone pairs of elec trons around the Br atom in BrF 3 than that in BrF2+. 7 Dimerisation is described as a process in which two identical molecules combine to give a single product. Some examples include Al2Cl6, N2O4 and (CH3CO2H)2. Which of the following statements about the above dimers are correct? 1 Hydrogen bonds hold the CH 3CO2H molecules together in the dimer. 2 All the nitrogen-oxygen bonds in N 2O4 are of equal length. 3 The bond angle around each aluminium atom in A l2Cl6 is 109.5°. A 1 only B 1 and 2 only C 2 and 3 only D 1, 2 and 3

4 River Valley High School 9729/01 [Turn over 2018 Preliminary Examinations 9 At T °C and a total pressure of 6.00 atm, N2O4 is 60.0% dissociated into NO2. What is the Kp value at T °C? A 3.0 B 5.4 C 13.5 D 21.6 10 H2A is a weak acid which undergoes partial dissociation. H2A(aq) ⇌ 2H+(aq) + A2−(aq) Given that the pH of 1.00 mol dm −3 H2A(aq) solution is 2.3, what is the degree of dissociation of H2A? A 2.50 × 10−3 B 5.01 × 10−3 C 1.26 × 10−5 D 1.26 × 10−7 11 The auto-ionisation of water is an endothermic process. H2O(l) ⇌ H+(aq) + OH−(aq) ΔH = +6.5 kJ mol–1 Which of the following statements are correct? 1 Kw increases as temperature increases. 2 pH of solution decreases as temperature increases. 3 Acidity of water increases as temperature increases. A 1 and 2 only B 1 and 3 only C 2 and 3 only D 1, 2 and 3 12 What is the pH of a saturated solution of aluminium hydroxide, Al(OH) 3, if its solubility product is 2.53 × 10−18 mol4 dm−12? A 4.28 B 5.44 C 9.60 D 9.72 8 Vaporisation is the process when a liquid is converted to a gas. Given that the enthalpy change of vaporisation of water is +40.8 kJ mol−1, what is the entropy change when 36.0 g of water boil to form water vapour? A +109 J K−1 B −109 J K−1 C +219 J K−1 D −219 J K−1

5 River Valley High School 9729/01 [Turn over 2018 Preliminary Examinations 13 The energy profile diagram of the reversible reaction between M and N is shown below. Which of the following statements are correct? 1 The activation energy of the reverse reaction is E 1 + E2. 2 Rate equation of the reaction is rate = k[M][N]2. 3 The equilibrium [ MN2] increases as temperature increases. A 1 and 2 only B 1 and 3 only C 2 and 3 only D 1, 2 and 3 MN2 progress of reaction energy M + 2N E1 MN + N E2

6 River Valley High School 9729/01 [Turn over 2018 Preliminary Examinations 14 The acid-catalysed reaction between X and Y2 in aqueous solution has been investigated. X + Y2(aq) H+ ⎯→⎯⎯ XY(aq) + HY (aq) It has been found that rate equation is rate = k[X][Y2]m[H+]n. The change in concentration of Y2 remaining for this reaction is measured by using a photoelectric colorimeter. Graph A is obtained when the concentration of hydrogen ions used is 0.1 mol dm–3. What is the overall order of reaction? A 0 B 1 C 2 D 3 Colorimeter reading ∝ conc. of Y2(aq) t /s Graph A (0.1 mol dm–3 H+) slope = mA Graph B (0.2 mol dm–3 H+) slope = mB = 2mA 0

7 River Valley High School 9729/01 [Turn over 2018 Preliminary Examinations 15 W and X are 2 different elements in Period 3. The following are some of their properties: - The oxide of W is insoluble in water, but is soluble in both NaOH(aq) and HCl(aq). - The chloride of X dissolves completely in water to give a colourless solution of pH = 2. Which of the following is the likely identity of element W and X? W X A Al P B Al Si C Mg P D Mg Si 16 Y and Z are two different elements from the same Group. The chlorides of both Y and Z have giant ionic lattice structure. Which of the following statements is inconsistent with the other options? A The first ionisation energy of Y is less endothermic compared to Z. B The oxide of Y is less soluble in water compared to the oxide of Z. C The magnitude of the lattice energy of chloride of Y is higher compared to the chloride of Z. D The carbonate of Y decomposes at a lower temperature compared to the carbonate of Z.

8 River Valley High School 9729/01 [Turn over 2018 Preliminary Examinations 17 Purification of copper involves placi ng the impure copper at the anode of an electrolytic cell of CuSO4(aq) and running a current though the setup. Over time, pure copper will be deposited on the cathode. In a particular setup, a copper sample with zinc and silver impurities was placed at the anode and a current of 6. 00 A was passed through the circuit for 11 min. The cathode was then found to have an increase of mass of 1.12 g. Which of the following statement is likely to be incorrect? A Less time is needed if [CuSO4] is increased. B Anodic sludge containing silver would be formed. C The maximum mass of copper that