2013 MI H1 Chemistry P1

Class Adm No Candidate Name: This question paper consists of 12 printed pages and 2 blank pages. [Turn over 2013 Promotional Examination II Pre-University 2 H1 CHEMISTRY 8872 / 01 24 September 2013 50 minutes Additional Materials: Multiple Choice Answer Sheet Data Booklet READ THESE INSTRUCTIONS FIRST INSTRUCTIONS TO CANDIDATES 1. Do not turn over this question paper until you are told to do so. 2. Write your name, class and admission number in the spaces provided at the top of this page and on the Answer Sheet provided. 3. Answer ALL questions and shade the correct answers on the Answer Sheet provided using a soft pencil. 4. No extra time will be given for shading. 5. Hand in the question paper and the Answer Sheet separately. INFORMATION FOR CANDIDATES Marks will not be deducted for wrong answers; your total score will be the number of correct answers given. FOR EXAMINER’S USE TOTAL (30 marks)

2 Answer all questions on the OMR form provided (30 Marks) Section A For each question, there are four possible answers, A, B, C and D. Choose the one you consider correct. 1. Which of the following have the same number of particles as 32.0 g of oxygen gas? A 2.0 g of hydrogen gas B 11.5 g of sodium metal C 24.0 g of carbon D 35.5 g of chlorine gas 2. 10 cm3 of a hydrocarbon C xHy was exploded with 100 cm 3 of oxygen. After cooling to room temperature, the resultant gaseous mixture has a volume of 80 cm 3. When the resultant gaseous mixture was treated with a solution of potassium hydroxide, the volume of the gaseous mixture decreased to 40 cm 3. What is the molecular formula of the hydrocarbon? [All gas volumes are measured at r.t.p.] A C 3H6 B C3H8 C C4H8 D C4H10 3. The metallic ion, Mx+, is oxidised to MO4 - by acidified K2Cr2O7 solution. A sample of 25.0 cm3 of 0.280 mol dm-3 aqueous Mx+ requires 23.30 cm3 of 0.200 mol dm-3 acidified K2Cr2O7 solution for complete reaction. What is the value of x in Mx+? [Cr2O7 2- + 14H+ + 6e¯ 2Cr3+ + 7H2O] A 1 B 2 C 3 D 4

[Turn over 3 4. Which of the following species in their ground states have three unpaired electrons? A Si B S C Fe3+ D Cr3+ 5. Which of the following species contains ionic, covalent and dative bonding within itself? A Al 2Cl6 B NH4SO4 C H2SO4 D H3O+ 6. Which of the following series of substances does not show a decreasing trend in boiling point? A BaCl2 > BCl3 > BF3 B CH3I > CH3Br > CH3Cl C AsH3 > PH3 > NH3 D CH3COONa > CH3COOH > CH3CH2OH 7. Which of the following reactions has a negative enthalpy change of reaction? A KOH(aq) + HCl(aq) → KCl(aq) + H 2O(l) B H2O(l) → H2O(g) C NaF(s) → Na+(g) + F (g) D Cl2(g)  2Cl(g)

4 8. Dinitrogen oxide, N=N=O, reacts with ethyne, H-C ≡C-H, in the gaseous phase to produce water vapour, carbon dioxide and nitrogen gases as the only products. 5N2O (g) + C2H2 (g)  H2O (g) + 2CO2 (g) + 5N2 (g) The enthalpy change of the reaction is -1710 kJ mol-1. Using appropriate information from the Data Booklet, calculate the N=O bond energy, in kJ mol-1, in dinitrogen oxide. A 390 B 686 C 784 D 1370 9. The enthalpy change of formation of aluminium oxide and copper( II) oxide is -1676 kJ mol -1 and -155 kJ mol -1 respectively. What is the enthalpy change of the following reaction? 2Al(s) + 3CuO(s)  Al2O3(s) + 3Cu(s) A -1521 kJ mol-1 B -1211 kJ mol-1 C +1211 kJ mol-1 D +2141 kJ mol-1 10. For the following equilibrium: 3Fe (s) + 4H2O (g) Fe3O4 (s) + 4H2 (g) Which is the correct expression for the equilibrium constant, Kc? A [Fe] 3 [H2O] 4 [Fe3O4] [H2] 4 B [Fe] 3 [H2O] 4 [Fe3O4] [H2] 4 C [H2O] 4 [H2] 4 D [H2O] 4 [H2] 4

[Turn over 5 % Z Temperature % Z Pressure 11. Consider the following equilibrium: PCl5 (g) PCl3 (g) + Cl2 (g) ∆H > 0 Which of the following statements is correct? A Increasing the temperature will decrease the yield of Cl2. B Increasing the pressure will decrease the yield of Cl2. C The equilibrium constant has a unit of mol2 dm-6. D The presence of a catalyst will increase the yield of Cl2. 12. A compound Z is formed during a gas phase reaction. The graphs below show how the percentage of Z present at equilibrium varies with temperature and pressure. Which of the following responses concerning the equilibrium is correct? Enthalpy change of reaction No. of gaseous particles in product No. of gaseous particles in reactant A Exothermic > 1 B Exothermic < 1 C Endothermic > 1 D Endothermic < 1 13. What is the pH of a solution prepared by dissolving 5.0 g of NaOH in 500 cm 3 of water? A 0.6 B 3.6 C 10.4 D 13.4

6 14. The following data was obtained from the studies of the reaction between O2 and N2O5 in a vessel at constant temperature. Which of the following statements is correct regarding the above system? Experiment 1 2 3 Initial total volume of O2 and N2O5 / cm3 1.00 1.60 2.00 Initial volume of O2 / cm3 0.60 1.20 1.20 Initial rate of reaction / cm3 s-1 2.06 4.12 16.48 A The rate equation is rate = k [O2]2. B The overall order of the reaction is three. C The rate constant k has units of cm-3s-1. D The reaction is first order with respect to N2O5. 15. In the diagram below, curve I was obtained from the decomposition of 250 cm 3 of 2.0 mol dm-3 hydrogen peroxide in the presence of manganese(IV) oxide as a catalyst at 25 C. Which alteration to the original experiment would produce curve II? A Using more manganese(IV) oxide. B Increasing the temperature. C Adding 50 cm 3 of 1.0 mol dm-3 hydrogen peroxide. D Adding 200 cm3 of water. Volume of O2 collected / cm3 Time / s II I

16. W tru A B C D 17. T h W A B C D 18. A re W A B C D Which of the ue? Increas The rat increas The rat The rat he graph sh What is the p Electric Atomic Melting Electro mixture of esulting solu What could b Na2O a NaCl a SiCl4 a Al2O3 a following st se in concen te constant sed. te constant te constant hows how a property? cal conducti radius g point negativity an oxide a ution has a be the cons and MgCl2 nd Na2O nd SiO2 and NaCl tatements a ntration of r decreases of different increases w property of vity and a chlor a pH of 2. stituents of 7 about the ra reactants wi when the a reactions c when a cata f the eleme ide of elem f the mixtur ate constant ill increase activation en can have dif alyst is used nts Na to C ments in Pe re? t of a chemi the rate con nergy of the fferent units d. Cl varies acr riod 3 is ad [Tu ical reaction nstant. e reaction is s. ross the per dded to wa urn over n is not riod. ter. The

8 19. Methyl butanoate, CH3OCOCH2CH2CH3, is responsible for the smell of pineapples. What are the products formed when methyl butanoate undergoes alkaline hydrolysis? A CH3COOH and CH3CH2CH2OH B CH3CH2CH2COOH and CH3OH C CH3CH2CH2COO- and CH3O- D CH3CH2CH2COO- and CH3OH 20. Which of the following reagents can be used to distinguish between compounds R and S shown below? C C H H OH O C H CC H O H Compound R CC O OH H H C H H OH Compound S A Na2CO3 B PCl5 C LiAlH4 in dry ether D acidified K2Cr2O7 21. 0.02 mol of alkene F requires 1.92 dm 3 of gaseous HBr for complete reaction at room temperature and pressure. How many double bonds are present in one molecule of F? A 2 B 3 C 4 D 5

[Turn over 9 22. Which of the following is not correct for compound A? C O CHO C H H C O CH3 compound A A It decolourises aqueous bromine. B It can be reduced by NaBH4 in ethanol. C It reacts with Fehling’s solution to give a brick-