VJC H2 CHEM P1 QN Prelim

 VJC 2014 9647/01/PRELIM/14 [Turn over VICTORIA JUNIOR COLLEGE JC 2 PRELIMINARY EXAMINATIONS Higher 2 CHEMISTRY 9647/01 Paper 1 Multiple Choice 24 September 2014 1 hour Additional Materials: Multiple Choice Answer Sheet Data Booklet READ THESE INSTRUCTIONS FIRST Write in soft pencil. Do not use staples, paper clips, highlighters, glue or correction fluid. Write your NRIC/FIN number, name and CT group on the Answer Sheet. There are forty questions. 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 choices 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 17 printed pages and 1 blank page.

2  VJC 2014 9647/01/PRELIM/14 Section A For each question there are four possible answers, A, B, C, and D. Choose the one you consider to be correct. 1 Compound X reacts with ethanoic acid in the presence of an H + catalyst to produce the compound below. What is the molecular formula of compound X? A C2H6O2 B C2H6O3 C C4H8O D C4H8O2 2 When T l+(aq) ions are reacted with VO 3 –(aq) ions, T l3+(aq) ions and V 2+(aq) ions are formed. Assuming the reaction goes to completion, how many moles of T l+(aq) and VO 3 –(aq) would result in a mixture containing equal number of moles of VO 3 –(aq) and V 2+(aq) once the reaction had taken place? moles of Tl+(aq) moles of VO3 –(aq) A 1 2 B 1 3 C 2 3 D 3 4 3 Which of the following contains only one unpaired electron? A Ga– B Se– C Te+ D As+ 4 Which of the following substances contains a central atom having eight electrons only? A NO2 B SO2 C F2O D ClO2 5 For which of the following pairs does the first species have a smaller bond angle? A SnCl2, OCl2 B H2O, H2S C I3 –, N3 – D NF3, NCl3

3  VJC 2014 9647/01/PRELIM/14 [Turn over 6 The value of PV is plotted against P at the same temperature for four gases, where P is the pressure and V is the volume of the gas. Which of the following represents the possible identities of gases W, X, Y and Z? W X Y Z A CH3CH2OH HCO2H CH3CHO CH3CH2CH3 B CH3CH2OH CH3CHO HCO2H CH3CH2CH3 C HCO2H CH3CH2OH CH3CHO CH3CH2CH3 D HCO2H CH3CHO CH3CH2OH CH3CH2CH3 7 Use of the Data Booklet is relevant to this question. Two cells are connected in series as shown in the diagram where E, F, G and H are electrodes. After the current is passed for some time, a t which electrode will there be the greatest change in mass? A E B F C G D H PV P W X Y Z Al2(SO4)3(aq) CuSO4(aq) Cu Al E F G H Cu Ag

4  VJC 2014 9647/01/PRELIM/14 8 Use of the Data Booklet is relevant to this question. A student carried out an experiment to determine the enthalpy change for the combustion of methanol. The following results were obtained by the student. initial temperature of the water: 20 oC final temperature of the water: 53 oC mass of alcohol burner before burning: 259.65 g mass of alcohol burner after burning: 259.15 g mass of beaker plus water: 150.00 g mass of beaker: 50.00 g How much of the heat energy produced by the burning of methanol went into the water? A 209 J B 13800 J C 20700 J D 22200 J 9 If N2O4 gas is placed in a sealed vessel, the following equilibrium is established. N2O4(g) ⇌ 2NO2(g) The forward reaction is endothermic. Which of the following is incorrect when the temperature is increased? A The equilibrium constant increases. B The partial pressure of NO2 increases. C The enthalpy change increases. D The activation energy is unchanged. 10 Which of the following equilibria is not affected by the addition of aqueous ammonia? A BaSO4(s) ⇌ Ba2+(aq) + SO4 2–(aq) B AgCl(s) ⇌ Ag+(aq) + Cl–(aq) C Fe(OH)3(s) ⇌ Fe3+(aq) + 3OH–(aq) D [Cu(H2O)6]2+(aq) + 4Cl–(aq) ⇌ [CuCl4]2–(aq) + 6H2O(l)

5  VJC 2014 9647/01/PRELIM/14 [Turn over 11 Human plasma is buffered mainly by dissolved CO 2 which has reacted to form carbonic acid. H2CO3(aq) ⇌ H+(aq) + HCO3 –(aq) Usually the pH of human plasma is 7.4. The acid dissociation constant, Ka, of carbonic acid is 7.90 x 10–7 mol dm–3. Which of the following statements is incorrect? A This buffer system can be prepared by mixing suitable amounts of sodium hydrogencarbonate and hydrochloric acid. B The ratio of [HCO3 –] to [H2CO3] in human plasma is 20 : 1. C Its pH value remains constant when diluted with water. D It has a pH value equal to the pKa value of carbonic acid. 12 The mechanism below has been proposed for the reaction of CHCl3 with Cl2. Step 1: Cl2(g) ⇌ 2Cl(g) fast Step 2: Cl(g) + CHCl3(g)  CCl3(g) + HCl(g) slow Step 3: CCl3(g) + Cl(g)  CCl4(g) fast Which of the following rate equations is consistent with this mechanism? A rate = k[CHCl3][Cl] B rate = k[CHCl3][Cl2] C rate = k[CHCl3][Cl2]1/2 D rate = 13 Consecutive elements X, Y and Z are in the third period of the Periodic Table. Element Y has the highest first ionisation energy and the lowest melting point of these three elements. What could be the identities of X, Y and Z? A sodium, magnesium, aluminium B magnesium, aluminium, silicon C aluminium, silicon, phosphorus D silicon, phosphorus, sulfur

6  VJC 2014 9647/01/PRELIM/14 14 The nitrates of beryllium and aluminium can undergo thermal decomposition similarly as magnesium nitrate. Using relevant data from the Data Booklet, which of the following shows the correct trend of the decomposition temperatures for these three compounds? A Mg(NO3)2 > Al(NO3)3 > Be(NO3)2 B Mg(NO3)2 > Be(NO3)2 > Al(NO3)3 C Be(NO3)2 > Al(NO3)3 > Mg(NO3)2 D Al(NO3)3 > Be(NO3)2 > Mg(NO3)2 15 The table below shows the results of experiments in which the halogens, X2, Y2 and Z2 were added to separate aqueous solutions containing X–, Y– and Z– ions. X–(aq) Y–(aq) Z–(aq) X2 no reaction no reaction Z2 formed Y2 X2 formed no reaction Z2 formed Z2 no reaction no reaction no reaction In which sequence is the solubility of the silver halides in aqueous ammonia arranged in increasing order? A AgX, AgY, AgZ B AgY, AgX, AgZ C AgY, AgZ, AgX D AgZ, AgX, AgY 16 Which of the following reactions of first row transition metal ions is correct? A Addition of NaOH(aq) to K2CrO4(aq) produces an orange solution of K2Cr2O7. B Addition of KI(aq) to Fe2(SO4)3(aq) produces a brown precipitate of FeI3. C Addition of concentrated HC l to CuSO 4(aq) produces a yellow solution of H2[CuCl4]. D Addition of Na2CO3(aq) to CrCl3(aq) produces a green precipitate of Cr2(CO3)3. 17 Use of the Data Booklet is relevant to this question. Which set of reagents, when added in the order shown below, would convert Fe3+(aq) to [Fe(CN)6] −(aq)? step 1 step 2 step 3 A Zn(s) CN−(aq) SO2(g) B I−(aq) CN−(aq) Cl2(g) C H2O2(aq) I−(aq) CN−(aq) D Ag(s) I−(aq) CN−(aq)

7  VJC 2014 9647/01/PRELIM/14 [Turn over 18 Which of the following r