YJC H1 Chem P1

YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE YISHUN JUNIOR COLLEGE PRELIMINARY EXAMINATION CHEMISTRY 8872/01 Higher 1 50 minutes Paper 1 Multiple Choice Additional materials: ORS Data Booklet READ THESE INSTRUCTIONS FIRST Write in soft pencil. Do not use staples, paper clips, highlighters, glue or correction fluid. Write your name and CTG on the ORS form and shade your register number. There are 30 questions on this paper. Answer all questions. For each question there are 4 possible answers A, B, C and D. Choose the one you consider correct and record your choice in soft pencil on the ORS. 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 question paper. This question paper consists of 15 printed pages

8872/YJC/P1/2009 2 Section A For each question there are four possible answers, A, B, C, and D. Choose the one you consider to be correct. 1 Chromium is obtained from the following reaction, . Calculate the percentage yield of chromium when 180 g of chromium is obtained from a reaction between 100 g of aluminium and 400 g of chromium(III) oxide. A 45.0% B 36.0% C 93.6% D 131% 2 When 10 cm3 of a gaseous hydrocarbon was exploded with 100 cm3 of oxygen, the residual gas occupied 70 cm3. After shaking these residual gases with aqueous sodium hydroxide, the final volume was 20 cm3. All volumes were measured at room temperature and pressure. Calculate the molecular formula of the hydrocarbon. A C5H10 B C5H12 C C7H12 D C7H14 3 In which one of the following is a redox reaction? A CuO + H2SO4  CuSO4 + H2O B C2H5CH2OH + Na  C2H5CH2ONa + H2 C NH3 + HCl  NH4Cl D Al2Cl6  2AlCl3

8872/YJC/P1/2009 3 4 A plasma is a gaseous mixture in which the atoms have been completely stripped of their electrons, leaving bare nuclei. Predict the identity of x, y and z. x y z A H He Be B Be H He C He Be H D Be He H 5 The successive ionisation energies, in kJ mol-1, of an element X are given below. 870 1800 3000 3600 5800 7000 13200 What is the number of valence electron(s) in the outermost shell of element X? A 4 B 5 C 6 D 7 Source x - + y z

8872/YJC/P1/2009 4 8 Which one of the following equations is used to define the first ionisation of bromine? A Br(g) + e-  Br-(g) B ½Br2(g) + e-  Br-(g) C Br(g)  Br+(g) + e- D ½Br2(g)  Br+(g) + e- 6 Which of the following does not have a macromolecular structure? A Diamond B Graphite C Silicon dioxide D Sodium chloride 7 In which of the following pairs does the first species have a larger bond angle than the second? A NH3, BF3 B SO32-, SO42- C ClO3-, BrO3- D H2O, H3O+

8872/YJC/P1/2009 5 9 Consider the energy cycle below involving calcium fluoride CaF2(s) Ca2+(aq) + 2F-(aq) Ca(s) + F2(g) Using the following data, calculate ΔHr. enthalpy change of formation of Ca2+ = -543 kJ mol-1 enthalpy change of formation of F- = -333 kJ mol-1 enthalpy change of formation of CaF2 = -1220 kJ mol-1 A -11 kJ mol-1 B +11 kJ mol-1 C -344 kJ mol-1 D +344 kJ mol-1 10 The table shows some data on two acid-base indicators. Colour change Indicator Approximate pH range acid alkali Bromocresol green 3.8 – 5.5 yellow blue Phenol red 6.8 – 8.5 yellow red Identify the colour change of a weakly acidic solution in the presence of each indicator. Bromocresol green Phenol red A Yellow Yellow B Yellow Red C Blue Yellow D Blue Red ΔHr

8872/YJC/P1/2009 6 11 Given the following reaction in a vessel: A(g) + B(g) 2C(g) + D(g) ∆Hθ < 0 Which of the following statement is correct? A Add a suitable catalyst and solvent to dissolve C will lead to an increase in rate of reaction and yield. B Increase temperature and increase pressure will lead to an increase in rate of reaction and yield. C Decrease the temperature and increase the pressure will lead to a decrease in rate of reaction and increase in yield. D Add a suitable catalyst and increase the pressure will lead to a decrease in rate of reaction but no change in yield. 12 Which of the following does not describe Kw, ionic product of water. A It has units mol2dm-6 B It increases when temperature increases C It has a numerical value of 1.0 x 10-14 at 25ºC D It is the equilibrium constant for the reaction where water breaks down to its elements.

8872/YJC/P1/2009 7 13 The radioactive decay of uranium-238 is the rate determining step in a series of changes in which lead is the final product formed. The radioactive decay is a first order reaction with a half-life of 4.5 x 109 years. What is the age of a rock sample (originally lead free) with uranium to lead ratio of 1:7 now? A 1.5 x 109 years B 2.25 x 109 years C 9.0 x 109 years D 13.5 x 109 years 14 Which one of the following graphs shows how the rate of reaction changes with time for an autocatalytic reaction (i.e. a reaction catalysed by one of the products in the reaction)? A C B D Rate 0 time 0 time Rate Rate 0 time Rate 0 time

8872/YJC/P1/2009 8 15 A mixture of the oxides of two elements of the third period is dissolved in water. The solution is approximately neutral. What could be the constituents of the mixture? A Al2O3 and MgO C Na2O and MgO B Na2O and P4O10 D SO3 and P4O10 16 The element antimony occurs in Group V of the Periodic Table. Which one of the following sets of oxidation numbers is antimony likely to