2019 JPJC Prelim H2 Chem P1 QP

 Jurong Pioneer Junior College [Turn Over NAME CLASS 18S JURONG PIONEER JUNIOR COLLEGE JC2 PRELIMINARY EXAMINATION 2019 CHEMISTRY 9729/01 Higher 2 Paper 1 Multiple Choice 26 September 2019 1 hour Candidates answer on separate paper. Additional Materials: Multiple Choice Answer Sheet Data Booklet READ THESE INSTRUCTIONS FIRST Write in soft pencil. Do not use staples, paper clips, glue or correction fluid. Write your name, class and exam index number on the Answer Sheet in the spaces provided unless this has been done for you. There are thirty questions on this paper. Answer all questions. For each question there are four possible answers A, B, C or D. Choose the one you consider correct and record your choice in soft pencil on the separate 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  Jurong Pioneer Junior College 9729/01/J2 PRELIMINARY EXAM/2019 1 In which of the following pairs do the molecules have similar shapes? A CO2 and SO2 B BF3 and NH3 C H2O and ClO2 D NO2+ and ClO2 2 A to H are consecutive elements with atomic numbers less than 20. The graph below shows their second ionisation energies (2nd IE). Which of the following statements is incorrect? A Element E is from Group 2. B H exists as tetratomic molecules. C The compound formed between A and G is a gas at room temperature. D The 2nd IE of B is lower than that of A due to inter electronic repulsion between its paired p electrons. 3 After an oil spillage at sea, a liquid hydrocarbon layer floats on the surface of the water. Which statements help to explain this observation? 1 Hydrocarbon molecules are not solvated by water. 2 There are onl y instantaneous dipoleinduced dipole interactions between hydrocarbon molecules. 3 Hydrogen bonding between water molecules causes water molecules to be packed closely together. A 2 only B 1 and 2 only C 2 and 3 only D 1, 2 and 3 2nd IE element

3  Jurong Pioneer Junior College 9729/01/J2 PRELIMINARY EXAM/2019 [Turn Over 4 The value of pV is plotted against p for two gases, J and L, where p is the pressure and V is the volume of the gas. Which of the following could be the identities of the gases? Gas J Gas L 1 0.5 mol of H2O at 25 C 0.5 mol of H2 at 50 C 2 0.5 mol of NH3 at 25 C 1 mol of CH4 at 25 C 3 0.25 mol of SO2 at 25 C 0.5 mol of H2 at 25 C A 2 only B 3 only C 2 and 3 only D 1, 2 and 3 5 Use of the Data Booklet is relevant to this question. Which statement about 28.0 g of nitrogen gas is correct? A It contains the same number of atoms as one mole of neon gas. B It contains the same number of molecules as 71.0 g of chlorine gas. C It has the same mass as one mole of carbon dioxide gas. D The gas occupies a volume of 24 dm3 at standard temperature and pressure. 6 Use of the Data Booklet is relevant to this question. An element M can exist in a few oxidation states. 15.00 cm 3 of an aqueous solution of 0.100 mol dm 3 of Mn+ required 20.00 cm 3 of 0.0250 mol dm3 of acidifed K2Cr2O7 solution for a complete reaction. What is the change in oxidation state of M? A 2 B 3 C 4 D 5 2x x pV p Gas L Gas J 0

4  Jurong Pioneer Junior College 9729/01/J2 PRELIMINARY EXAM/2019 7 Use of the Data Booklet is relevant to this question. A s tudent carried out an experiment under laboratory conditions and the following resul ts were obtained. Given that the enthalpy change of co mbustion of ethanol is 1367 kJ mol1, what is the efficiency of heat transfer in the above experiment? A 60.7% B 81.1% C 82.9% D 83.2% 8 Hydrogen can be made from steam as shown. H2O(g) + C(s)  H2(g) + CO(g) The Gibbs free energy change of the reaction is +78 kJ mol1 at 378K. Which statement about the reaction is not correct? A The entropy change is positive. B The products are energetically less stable than the reactants C The Ecell value of the reaction is positive. D The reverse reaction is spontaneous. 9 The table below gives data for the reaction between N and Q at constant temperature. Experiment [N] / mol dm3 [Q] / mol dm3 Initial rate / mol dm3 min1 1 0.003 0.2 4.0  104 2 0.006 0.4 1.6  103 3 0.006 0.8 6.4  103 Which statement about the reaction is not correct? A The reaction is elementary. B The rate constant k has the units of mol‒1 dm3 min1. C The halflife of N is not constant. D The order of reaction with respect to [Q] is 2. initial temperature of the water 28.0 °C final temperature of the water 50.4 °C mass of ethanol burner before burning 259.400 g mass of ethanol burner after burning 259.286 g mass of water used 30.000 g thermometer metal calorimeter water spirit burner ethanol

5  Jurong Pioneer Junior College 9729/01/J2 PRELIMINARY EXAM/2019 [Turn Over 10 Poly(tetrafluoroethene) is a polymer used as a coating in non stick kitchen utensils and for replacement of bone joints. One of the stages in the manufacture of the polymer is 2CHClF2(g) ⇌ C2F4(g) + 2HCl(g) ∆Hc = +128 kJ mol1 Which statement correctly describes the effect of the change applied? A The equilibrium position will shift to the left when the reaction vessel is expanded. B The equilibrium concentration of CHClF2 decreases when the reaction vessel is cooled. C The addition of a catalyst will increase the equilibrium concentration of C2F4. D The equilibrium constant, Kc, increases when the reaction vessel is heated. 11 The diagram below shows the change of pH produced by gradually adding 0.100 mol dm −3 aqueous ethanoic acid to 10.0 cm3 of 0.100 mol dm−3 aqueous sodium hydroxide. At which point on the graph does pH = p Ka, where Ka is the acid dissociation constant of ethanoic acid? C D A B pH Volume of ethanoic acid added/ cm3

6  Jurong Pioneer Junior College 9729/01/J2 PRELIMINARY EXAM/2019 12 The following tests were performed on an aqueous solution to identify the unknown ions it contains. Step Test Observations 1 Add AgNO3(aq) followed by excess dilute NH3(aq). Swirl and filter the mixture. Yellow residue and colourless filtrate obtained. 2 Add Cl2(aq) to filtrate. Orange solution formed. Which statements are correct? 1 I ion is present in the mixture as the yellow AgI residue was obtained due to the low Ksp of AgI. 2 Br ion is present in the mixture as it undergoes disproportionation reaction with Cl2(aq). 3 Br ion and [Ag(NH3)2]+ ion are present in the filtrate. A 1, 2 and 3 B 1 and 3 only C 2 and 3 only D 1 only 13 Use of the Data Booklet is relevant to this question. The graph below shows the variation in electromotive force (emf) of the following electrochemical cell with lg [T+(aq)] at 298 K. Cu(s) | Cu2+(aq, 1 mol dm3) || T+(aq) | T(s) Which statement is not correct? A T(s) is the positive electrode. B The direction of electron flow in the external circuit will be reversed when the concentration of T+(aq) is 1.00  105 mol dm3. C The emf of the given cell under standard conditions will be +0.46 V. D The standard electrode potential of the T+(aq) | T(s) halfcell is +0.80 V. emf / V 0.46 7.80 0 lg [T+(aq)]

7  Jurong Pioneer Junior College 9729/01/J2 PRELIMINARY EXAM/2019 [Turn Over 14 Use of the Data Booklet is relevant to this question. A piece of aluminium ob ject was placed in dilute sulfuric acid and anodi se