IJC 2008 H2 Chemistry Prelim II Paper1

1 INNOVA JUNIOR COLLEGE JC 2 PRELIMINARY EXAMINATIONS 2 in preparation for General Certificate of Education Advanced Level Higher 2 CANDIDATE NAME CLASS INDEX NUMBER CHEMISTRY Paper 1 Multiple Choice Additional Materials: Data Booklet Multiple Choice Answer Sheet. 9746/01 17 September 2008 1 hour READ THESE INSTRUCTIONS FIRST Write your name and class on all the work you hand in. Write in soft pencil. Do not use staples, paper clips, highlighters, glue or correction fluid. There are forty 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 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. This document consists of 15 printed pages and 1 blank pages. Innova Junior College [Turn over

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 Acidified aqueous potassium dichromate(VI) oxidizes ethanedioate ions, C2O4 2-, to CO2. What volume of 0.020 mol dm -3 potassium dichromate( VI) is required to oxidize completely 1.0 x 10-3 mol of the salt KHC2O4·H2C2O4? A 17 cm3 C 50 cm3 B 33 cm3 D 125 cm3 2 Nervous disorders due to mercury poisoning occur when mercury forms a 1:1 complex with lipoyl groups, which are vital for glucose metabolism. For a human containing 3.0 kg of body fluid, what is the mass of mercury (A r 200) required to complex all the lipoyl groups? [Average concentration of lipoyl groups in body fluid = 1.0 x 10-8 mol kg-1] A 1.5 x 10-9 g C 6.0 x 10-8 g B 3.0 x 10-8 g D 6.0 x 10-6 g 3 When methane, CH 4, was burned in an incorrectly adjusted burner, it was converted into a mixture of carbon dioxide and carbon monoxide in the ratio 99:1, together with water vapour. What is the volume of oxygen consumed when 4 dm3 of methane is burned? A 7.98 dm3 C 3.98 dm3 B 7.96 dm3 D 3.96 dm3 4 Tritium, , is an isotope of hydrogen atom. 3 1 H Given that a 2 g sample of hydrogen at temperature T and volume V exerts a pressure p , which of the following would also exert a pressure p at the same temperature T? A a mixture of 1 g of hydrogen and 1 g of tritium of total volume 3V B a mixture of 3 g of hydrogen and 1 g of tritium of total volume V C a mixture of 1 g of hydrogen and 3 g of tritium of total volume V D a mixture of 3 g of hydrogen and 1 g of tritium of total volume 3V © INNOVA 2008 9746/01/2008 [Turn over

3 5 Which of the following atoms or ions has 1 unpaired electron? A N– B O C S2– D Zn+ 6 Which of the following molecules do not have all the atoms lying on the same plane? A H2O B ICl3 C PH3 D BrCl4- 7 Why is ethanol more soluble than ethyl ethanoate in water? A A hydrogen bond forms between the hydrogen of the –OH group in ethanol and the hydrogen of a water molecule. B A hydrogen bond forms between the hydrogen of the –OH group in the ethanol and the oxygen of a water molecule. C Ethanol is a polar molecule, but ethyl ethanoate is non-polar. D Ethanol is able to dissociate into hydrogen ions and ethoxide ions, but ethyl ethanoate is not able to dissociate. 8 S and Q are two isotopes of a radioactive element, with half-lives of 5 min and 10 min respectively. An experiment begins with equal number of radioactive atoms of S and Q which decay to give S’ and Q’ respectively. How long will it take for S’:Q’ ratio to be 5:4, given that the radioactive decay is a first-order reaction? A 10 min C 30 min B 20 min D 40 min 9 Nitrogen, being an unreactive gas, is frequently used as an inert atmosphere. Which of the following gives the best explanation for its unreactivity? A Its molecule contains a triple bond. B The three p-orbitals of nitrogen are fully-filled. C The bond in its molecule is short (0.110 nm). D The bond energy of the molecule is high (994 kJ mol -1). © INNOVA 2008 9746/01/2008 [Turn over

4 10 % of product Pressure Which of the following reaction will have the graph shown above? A H2(g) + I2(g) 2H I (g) B N2(g) + 3H2(g) 2NH 3(g) C CaCO3(s) CaO(s) + CO 2(g) D N2O4(g) 2NO 2(g) 11 The enthalpy change of reaction between calcium and water, ∆Hr, can be measured in the laboratory. Ca(s) + 2H2O(l) Æ Ca(OH)2(s) + H2(g); ∆Hr What other data is needed in order to calculate the enthalpy change of formation of Ca(OH)2(s)? A Enthalpy change of atomisation of calcium B Enthalpy change of combustion of hydrogen C First and second ionisation energies of calcium D Lattice energy of calcium hydroxide 12 The solubility of barium sulphate is 0.0025 g dm -3. What mass of barium sulphate can be dissolved in 2.0 dm3 of 0.0200 mol dm-3 of sulphuric acid? (Mr of BaSO4 = 233.1) A 2.68 x 10-6 g C 0.68 x 10-6 g B 1.34 x 10-6 g D 0.34 x 10-6 g 13 A current was passed through two cells connected in series. The first cell contained molten magnesium chloride while the other contained molten chromium ( III) chloride. If 4.8 g of magnesium was liberated from the first cell, the mass of chromium liberated from the other cell will be A 2.4 g C 6.8 g B 3.2 g D 15.6 g © INNOVA 2008 9746/01/2008 [Turn over

5 14 A tiny magnesium electrode which creates an electrical cell with inhaled oxygen could be used in the construction of heart pacemakers. From the relevant half-cells: Mg2+ + 2e Mg E θ= – 2.38 V ½O2 + 2H+ + 2e H 2O Eθ= +1.23 V the cell e.m.f would be +3.61V under standard conditions. However, in the body, a potential of +3.25V is more common. Which of the following gives the best explanation for this lower e.m.f? A the small size of the magnesium electrode B the low concentration of Mg2+ ions surrounding the magnesium electrode C the high resistance of the body fluids surrounding the electrodes D the pH of between 7 and 8 of the body fluid surrounding the electrodes 15 Three types of oxides required to make coloured glass in church windows are one macromolecular, one ionic and one of a transition metal. Which of the following combinations of oxides is likely to produce a coloured glass? A Al2O3, MgO, SnO C P4O10, CaO, CuO B SiO2, CaO, PbO D SiO2, PbO, CoO 16 Which one of the following statements about Group II elements (Be to Ba) is correct? A The reactivity with cold water decreases down Group II metals. B The charge density of Group II cations increases from Be to Ba. C The solubility of the sulphates increases from Be to Ba. D The thermal stability of the Group II carbonate increases from Be to Ba. 17 For which one of the following metal complexes is the electronic configuration wrong? Complex Electronic configuration of central metal ion A [Zn(NH3)4]2+ [Ar] 3d10 B [Co(H2O)6]3+ [Ar] 3d6 C [Cu(NH3) 4]2+ [Ar] 3d10 D [Ni(CN)6]4- [Ar] 3d8 © INNOVA 2008 9746/01/2008 [Turn over

6 18 How many different tripeptides can be formed from glycine and alanine amino acids? C H H2N C CH3 alanine O OH C