MI H1 CHEM P1 Promo

Class Adm No Candidate Name: Promotional Examination II 2009 Pre-university 2 H1 CHEMISTRY 8872 PAPER 1 8872 / 1 Tuesday 15 September 2009 50 m Additional materials: OMR Data Booklet INSTRUCTIONS TO CANDIDATES 1. Do not turn over this question paper until you are told to do so. 2. Write your name, class and index number in the spaces provided at the top of this page and on the OMR provided. 3. Answer ALL questions and shade the correct answers on the OMR provided. 4. Hand in the question paper and the OMR separately. FOR EXAMINER’S USE Section Total Marks 30 INFORMATION FOR CANDIDATES Marks will not be deducted for wrong answers; your total score on this test will be the number of correct answers given. This question paper consists of 13 printed pages.

2 SECTION A (25 marks) For each question, there are four possible answers, A, B, C and D. Choose the one you consider correct. 1. Which statement is FALSE ? A One mole of 12C has a mass of 12.00g. B One mole of methane contains 75% of carbon by mass. C One mole of methane contains four moles of hydrogen atoms. D One mole of hydrogen gas contains 6.02  1023 atoms of hydrogen. 2. A 1.881 g sample of an unknown metallic carbonate is decomposed by heating to form the metallic oxide and 0.66 g of carbon dioxide according to the equation: MCO 3(s)  MO(s) + CO2(g) What is metal, M? A Ca B Mn C Ni D Zn 3. In an experiment, 50 cm 3 of a 0.1 mol dm -3 solution of a metallic salt reacted exactly with 25 cm3 of 0.1 mol dm -3 sodium sulphite solution. The half equation for oxidation of sulphite ion is SO3 2- (aq) + H2O (l)  SO4 2- (aq) + 2H+ (aq) + 2e- If the original oxidation number of the metal in the salt was +3, what would be the new oxidation number of the metal? A 0 B +1 C +2 D +4

3 4. When 20 cm 3 of a gaseous hydrocarbon was completely burnt in an excess of oxygen, 60 cm3 of carbon dioxide and 60 cm 3 of water vapour were formed, all volumes being measured at the same temperature and pressure. What is the molecular formula of the hydrocarbon? A CH 2 B C 2H6 C C 3H6 D C 3H8 5. Why is the first ionisation energy of sulphur lower than that of phosphorus? A Sulphur forms an anion more readily. B Sulphur is more electronegative than phosphorus. C The sulphur atom is larger than the phosphorus atom. D The electron to be lost is paired with another electron. 6. Which of the following ions will be deflected the least when passed through an electric field? A 2 24 12 Mg B 3 27 13 Al C 2 16 8 O D 3 31 15 P 7. X and Y are elements with the following succe ssive ionisation energies in kJ mol-1. X 580 1800 2700 11600 14800 18400 23300 Y 1310 3400 5300 7500 11300 13300 35000 What is the compound that is formed from element X and Y? A XY 4 B X2Y3 C X 3Y2 D X4Y [Turn Ove r]

4 8. Which of the following molecules do not have all the atoms lying on the same plane? A PH 3 B H2O C ICl3 D BrCl4 – 9. Which one of the following shows increasing magnitudes of angles X, Y and Z? A Y < Z < X B Z < X < Y C X < Z < Y D Z< Y < X 10. Three substances, X, Y and Z have physical properties as shown. Electrical Conductivity Substance Melting point /°C Boiling point /°C of solid of molten X 801 1413 poor good Y 2852 3600 poor good Z 3550 4827 good not known What could be the identities of X, Y and Z? X Y Z A NaF BeC l 2 Cu B NaCl MgO graphite C NaBr CaO SiO 2 D NaI Al2O3 diamond

5 11. The table below give the enthalpy change of combustion of ethyne (C 2H2), hydrogen (H2) and ethane (C2H6). Compound Hc / kJ mol-1 Ethyne -1300 Hydrogen -285 Ethane -1560 What is the enthalpy change for the following reaction? C 2H2(g) + 2H2(g)  C2H6(g) A +130 kJ B +155 kJ C -155 kJ D -310 kJ 12. For which of the following reactions does the value of H  rxn represent both a standard enthalpy change of combustion and a standard enthalpy change of formation of a substance? A 2S (s) + O 2 (g)  2SO2 (g) B S (g) + O 2 (g)  SO2 (g) C S (s) + O 2 (g)  SO2 (g) D SO (g) + O 2 (g)  SO2 (g) 13. If the reaction P + Q  R + S is described as being zero order with respect to P, which of the following statements best describes P? A P is a catalyst in the above reaction. B The concentration of P does not change during the reaction. C There are no P molecules which possess sufficient energy to react. D The rate of reaction is independent of the concentration of P. [Turn Ove r]

6 14. The decomposition of dinitrogen pentoxide, N 2O5, was found to be first order with respect to N2O5. Which one of the following graphs confirms the result? A B C D 15. In the diagram, curve G was obtained by observing the decomposition of 100 cm3 of 1.0 mol dm-3 of hydrogen peroxide, catalysed by manganese (IV) oxide. Which alteration to the original experimental conditions would produce curve H? A Adding water B Increasing the temperature G H Volume of O2 formed Time 0 Rate of decomposition Rate of decomp osition [N2O5] [N2O5] Rate of decomp osition [N2O5] [N2O5] Rate of decomposition

7 C Using less manganese (IV) oxide D Adding some 0.1 mol dm -3 hydrogen peroxide 16. Compound X decomposes upon heating according to the following equation: 2X (s) Y (g) + 2Z (g) When 5 mol of X were put into a 1 dm3 container and heated, the equilibrium mixture contained 0.6 mol of Y. What is the approximate numerical value of the equilibrium constant Kc? A 0.060 B 0.094 C 0.189 D 0.864 17. Two experiments were performed involving the following equilibrium. H 2(g) + I2(g) 2HI(g); H = +54 kJ mol–1 In experiment (1) carried out at temperature T1 K, the equilibrium constant, Kc = 64. In a separate experiment (2), 1.0 mol of H 2 and 1.0 mol of I2 were initially added into a 1 dm3 flask. The flask was found to contain 1.2 mol of HI at equilibrium. What can you infer from the data? A 1.2 mol of H I was present at equilibrium in experiment (1). B Total pressure was reduced in experiment (1). C Temperature in experiment (1) is diff erent from that in experiment (2). D The relationship between T 1 and T2 cannot be determined. [Turn Ove r]

8 18. In separate experiments, 1 mol eac h of the chlorides of the el ements sodium to chlorine is added to water. Which of the following diagr ams best represents how the pH of the solutions produced varies with the atomic number of the elements? 19. Which is the following process known as? CH3 CH3 Cl A nucleophilic addition B nucleophilic substitution C electrophilic substitution D electrophilic addition

9 20. Which reagent gives the same visible result with propanal and with propan-2-ol? A Fehling’s reagent B concentrated sulphuric acid C acidified potassium manganate(VII) D 2,4-dinitrophenylhydrazine 21. CC H 2 CH3 undergoes a series of reactions as shown. CC H 2 CH3 Cl2 dark Br2 FeBr3 product What is the structural formula of the product formed? A C CH3 Cl CH3Br B C CH 3 Cl CH2Cl Br C C CH 3 Cl CH2ClBr D C CH 3 CH2BrCl Br [Turn Ove r]

10 22. Compound W has the following structure: OH CH2Br Cl Which compound is obtained when compound W is heated with aqueous alcoholic KCN? A OH CH2Br Cl CN CN C OH CH2CN CN B OH CH2CN Cl D CH2CN Cl CN 23. X, Y and Z are three organic compounds. X undergoes oxidation with hot acidified potassium manganate(VII) to give Y and Z . Y gives a orange precipitate with 2,4- dinitrophenylhydrazine but gives negativ