DHS H2 CHEM P1 Prelim

This question paper consists of 15 printed pages and 1 blank page. © DHS 2011 [Turn over Name: Index Number: Class: DUNMAN HIGH SCHOOL Preliminary Examination Year 6 H2 CHEMISTRY 9647/01 Paper 1 Multiple Choice 27 September 2011 1 hour Additional Materials: Optical Mark Sheet Data Booklet INSTRUCTIONS TO CANDIDATES 1 Write your name and class on this question paper. 2 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 Optical Mark Sheet. 3 Each correct answer will score one mark. A mark will not be deducted for wrong answer. 4 Any rough working should be done in this booklet. 5 You may use a calculator.

2 © DHS 2011 9647/01 [Turn over Section A For each question, there are four possible answers A, B, C, and D. Choose the one you consider to be correct. 1 Samples of 10 cm 3 of each of the first four members of the alkane series are separately mixed with 70 cm 3 of oxygen. Each is then burned and the total volume, V, of the residual gas measured again at room temperature and pressure. Which graph represents the results that would be obtained? A B C D 2 In a historically famous experiment Wöhler heated ‘inorganic’ ammonium cyanate in the absence of air. The only product of the reaction was ‘organic’ urea, CO(NH 2)2. No other products were formed in the reaction. What is the formula of the cyanate ion present in ammonium cyanate? A CNO– B CNO2– C CO– D NO– CH4 C 3H8 C2H6 C4H10 CH4 C 3H8 C2H6 C4H10 80 60 40 20 0 80 60 40 20 0 CH4 C 3H8 C2H6 C4H10 CH4 C 3H8 C2H6 C4H10 80 60 40 20 0 80 60 40 20 0 80 60 40 20 0 80 60 40 20 0

3 © DHS 2011 9647/01 [Turn over 3 Which of the following helps to explain the existence of a large number of stable metallic ionic oxides? A Oxygen is too electronegative to form covalent bonds. B The enthalpy change of atomisation of oxygen is low. C Most metals have large ionisation energies. D The lattice energies of the oxides counterbalance the unfavourable electron affinity of oxygen. 4 Which of the following has the same value as the standard enthalpy change of formation of carbon monoxide? [Hc  and Hf  represent the standard enthalpy change of combustion and formation respectively.] A ½Hc  (C(graphite)) B Hf  (CO2) – Hc  (C(graphite)) C Hf  (CO2) – ½Hc  (C(graphite)) D Hc  (C(graphite)) – Hc  (CO) 5 The use of the Data Booklet is relevant to this question. Spatulas are often made from nickel. Which aqueous solution should not be stirred with a nickel spatula because a reaction could occur? A Co 2+ (aq) B Fe3+ (aq) C Mn2+ (aq) D V2+ (aq) 6 The reaction between P and Q in aqueous solution is acid–catalysed, and the reaction is first order with respect to the hydrogen ion. If all other conditions are kept constant, what is the ratio of ? 1 pH at reaction of rate 3 pH at reaction of rate A 0.01 B 0.33 C 1 D 3

4 © DHS 2011 9647/01 [Turn over 7 When a KI solution is added to a solution of mercury( II) chloride, a precipitate of mercury( II) iodide is formed. A student plotted the mass of the precipitate formed versus the volume of potassium iodide solution added and obtained the following graph. What can be a possible explanation for the shape of the graph? A After a certain amount of KI added, no more precipitate is formed and the concentration of HgI 2 decreases with more KI added. B Mercury(II) iodide is soluble in excess KI because of the common ion effect. C Mercury(II) iodide reacts with excess KI to form a soluble complex. D When more KI is added, the ionic product of the solution becomes less than the solubility product and more HgI2 dissolves. 8 In some fireworks there is a reaction between powdered aluminium and powdered barium nitrate in which heat is evolved and an unreactive gas is produced. What is the equation for this reaction? A 2Al + Ba(NO 3)2  Al2O3 + BaO + 2NO B 4Al + 4Ba(NO3)2  2Al2O3 + 4Ba(NO2)2 + O2 C 10Al + 3Ba(NO3)2  5Al2O3 + 3BaO + 3N2 D 10Al + 18Ba(NO3)2  10Al(NO3)3 + 18BaO + 3N2 9 Which group of particles is in order of increasing size? A N O F B N3– O 2– F – C Na+ Mg 2+ Al 3+ D Na+ Ne F – volume of KI added / cm3 mass of HgI2 formed / g 0

5 © DHS 2011 9647/01 [Turn over 10 Consecutive elements X, Y, Z are in the third period of the Periodic Table. Element Y has the highest first ionisation energy and the lowest melting point. What could be the identities of X, Y and Z? A aluminium, silicon, phosphorus B magnesium, aluminium, silicon C silicon, phosphorus, sulfur D sodium, magnesium, aluminium 11 Two properties of non–metallic elements and their atoms are as follows.  property 1 has an oxide that can form a strong acid in water  property 2 has no paired 3p electrons Which properties do silicon and sulfur have? silicon sulfur A 1 and 2 1 only B 1 and 2 1 and 2 C 2 only 1 only D 2 only 1 and 2 12 The oxide and chloride of an element W are separately mixed with water. The two resulting solutions have the same effect on litmus. What is element W? A sodium B magnesium C aluminium D phosphorus

6 © DHS 2011 9647/01 [Turn over 13 Aluminium chloride catalyses certain reactions by forming carbocations (carbonium ions) with chloroalkanes as shown. RCl + AlCl 3  R+ + AlCl4 – Which property makes this reaction possible? A Aluminium atom in AlCl3 has an incomplete octet of electrons. B Chlorine atom in RCl has a vacant p orbital. C AlCl3 exists as the dimer Al2Cl6 in the vapour. D AlCl3 is a covalent molecule. 14 Use of the Data Booklet is relevant to this question. The sketch graph shows the variation of one physical or chemical property with another for the Period 3 elements. What are the correct labels for the axes? x–axis y–axis A atomic number mass number B atomic number melting point C first ionisation energy atomic number D first ionisation energy atomic radius 15 Due to their similar ionic radii, the reactions of lithium and magnesium and their corresponding compounds are very similar. Which statement concerning the reactions of lithium and its compounds is correct? A Lithium carbonate decomposes on heating at a relatively low temperature, forming lithium oxide and carbon dioxide. B Lithium nitrate decomposes on heating, forming lithium nitrite and oxygen. C Lithium burns only slowly in oxygen. D Lithium reacts violently with cold water, liberating hydrogen.

7 © DHS 2011 9647/01 [Turn over 16 Which property of Group II elements (beryllium to barium) decreases with increasing atomic number? A reactivity with water B second ionisation energy C solubility of hydroxides D stability of the carbonates 17 In black and white photographic film, light converts silver chloride into metallic silver. After the film has been developed, the unreacted silv er chloride is removed by reaction with sodium thiosulfate to produce a ‘fixed’ negative. AgCl + 2Na 2S2O3  4Na+ + Cl– + [Ag(S2O3)2]3– What is the function of the thiosulfate ion? A to make the silver ions soluble B to oxidise the silver ions C to oxidise the silver metal D to reduce the silver ions 18 Mohr’s salt is a pale green crystalline solid which is soluble in water. It is a ‘double sulfate’ which contains two cations, one of which is Fe 2+. The identity of the second cation is determined by heating solid Mohr’s salt with solid sodium hydroxide and a colourless gas is evolved. The gas readily dissolves in water giving an alkaline solution. A grey–gr