MJC H1 CHEM P1 W ANS

Name: _____________________ Class: ________ Reg Number: _____ MERIDIAN JUNIOR COLLEGE JC2 Preliminary Examination Higher 1 ___________________________________________________________________ CHEMISTRY 8872 / 01 Paper 1 Multiple Choice 23 September 2011 50 minutes Additional Materials: Multiple Choice Answer Sheet Data Booklet ___________________________________________________________________ READ THESE INSTRUCTIONS FIRST Write your name, class and register number in the spaces at the top of this page. Write in soft pencil. Do not use staples, paper clips, highlighters, glue or correction fluid. There are thirty 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 13 printed pages (excluding this cover page). Use of Answer Sheet Ensure you have written your name, class register number and class on the OMR Answer Sheet. Use a 2B pencil to shade your answers on the OMR sheet; erase any mistakes cleanly. Multiple shaded answers to a question will not be accepted. For shading of class register number on the OMR sheet, please follow the given examples: If your register number is 1, then shade 01 in the index number column. If your register number is 21, then shade 21 in the index number column.

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[Turn Over 1 Section A For each question, there are four possible answers A, B, C and D. Choose the one you consider to be correct. 1 A 10 cm 3 sample of ethanethiol, CH 3CH2SH, was exploded with 80 cm 3 of oxygen according to the given equation: CH3CH2SH + 9 2 O2  2 CO2 + SO2 + 3 H2O The resultant gas mixture was c ooled to room temperature and passed through aqueous sodium hydroxide. Wh at would be the final volume of gas(es) in the resultant mixture? A 10 cm 3 B 35 cm 3 C 45 cm 3 D 75 cm 3 2 When hydrogen peroxide is added to acidified potassium dichromate( VI), the reaction that occurs is: Cr2O7 2- + 3H2O2 + 8H+  2Cr3+ + 3O2 + 7H2O Which of the following statements is incorrect for this reaction? A The colour changes from orange to green. B The hydrogen peroxide acts as a reducing agent. C The oxidation number of oxygen does not change. D There is bubbling observed as the reaction proceeds.

[Turn Over 2 3 Which pair of species exhibit identical deflections in an electric field? A 14N+ and 14N- B 14N+ and 28Si2+ C 16O2- and 4He2+ D 16O2- and 32S2- 4 Which of the following pairs of subst ances have the same types of structure and bonding? A A lF3 and A lCl3 B HF and HC l C CO 2 and C D SiO 2 and Si 5 Which of the following statements regarding the NH2 - ion is correct? A It has a linear shape around the N atom. B It is the conjugate acid of NH 3. C The bond angle of NH 2 - is smaller than that of NH3. D There is a dative bond in the ion. 6 In which of the following reactions will the enthalpy change correspond to an enthalpy change of formation? A 2H 2 (g) + O2 (g)  2H2O (g) B Na (s) + C l (g)  NaCl (s) C Mg 2+ (g) + O2- (g)  MgO (s) D K (s) + Mn (s) + 2O 2 (g)  KMnO4 (s)

[Turn Over 3 7 Look at the energy cycle below. CH4(g) + 2O2(g) CO 2(g) + 2H2O(l) C(s) + 2H 2(g) + 2O2(g) Given that the Hf o(CH4) = – 75 kJ mol -1, Hf o(CO2) = – 393 kJ mol -1, and Hf o(H2O) = – 286 kJ mol -1, what is the standar d enthalpy change of combustion of methane? A – 604 kJ mol -1 B – 754 kJ mol -1 C – 890 kJ mol -1 D – 1040 kJ mol -1 8 An equilibrium can be repres ented by the following equation. 2L (s) + M (g) N (g) + 2P (g) When 2 mol of L and 1 mol of M were placed in an empty 1 dm3 container and heated, the equilibrium mixture contained 0.48 mol of L. What is the numerical value of the equilibrium constant, Kc, at the temperature of the experiment? A 4.8 B 7.3 C 9.8 D 32

[Turn Over 4 9 Bromocresol green is an acid-base indica tor with a pH range of 3.8 to 5.4. The acidic colour of the indicator is yellow and the alkaline colour is blue. Two drops of the indicator are added to each of the four aqueous solutions listed below. Which solution has its colour not correctly stated? S o l u t i o n C o l o u r A Aqueous H 2SO4 of concentration 1.0 x 10-4 mol dm-3 yellow B Aqueous Na 2SO4 of concentration 2.0 x 10-5 mol dm-3 blue C Aqueous HC l of concentration 3.0 x 10–5 mol dm–3 yellow D Aqueous NaC l of concentration 5.0 x 10-6 mol dm-3 blue 10 In an acid-base titration, a 0.10 mol dm -3 solution of an acid is added to 10 cm3 of a 0.10 mol dm-3 solution of an alkali. The pH value of the solution is plott ed against the volume, V, of acid added as shown in the diagram. This diagram could represent a titration between A CH 3CO2H(aq) and Ba(OH)2(aq) B CH 3CO2H(aq) and KOH(aq) C H 2SO4(aq) and KOH(aq) D H 2SO4(aq) and Ba(OH)2(aq) 0 pH 14 10 20 30 40 7 Volume of acid / cm3

[Turn Over 5 11 Bromine is formed by t he reaction between bromate( V) ions and bromide ions and acid: BrO3 - (aq) + 5Br - (aq) + 6H+ (aq)  3Br2 (aq) + 3H2O (l) The results of some experiments on the reaction are shown below. Experiment Concentration / mol dm-3 Initial rate / mol dm-3 s-1 BrO3 - Br - H + 1 0.10 0.10 0.10 1.2 x 10 -3 2 0.10 0.30 0.10 3.6 x 10 -3 3 0.20 0.10 0.10 2.4 x 10 -3 4 0.20 0.10 0.20 9.6 x 10 -3 Which statement is true based on the above data? A The overall order of reaction is three. B The rate of reaction is independent of [BrO 3 -]. C The units of the rate constant is mol -3 dm9 s-1. D The time taken for the concentration of Br - to decrease to half its initial value is the same for Experiment 1 to 4. 12 Which of the following statements about the properties of a catalyst is correct? A A catalyst increases the average kinetic energy of the reacting particles. B A catalyst decreases the rate of the reverse reaction. C A catalyst has no effect on the enthalpy change of the reaction. D A catalyst does not react and hence remains chemically unchanged at the end of the reaction.

[Turn Over 6 13 Q , R, S, and T are elements in Period 3 of the Periodic Table. Amongst all the elements in Period 3, Q has the largest ionic radius, R has the highest electrical conductivity, S has the highest melting point and T has highest first ionisation energy. Which of the following sequences shows correctly the elements in increasing proton number? A T, Q, R, S B T, R, S, Q C R, S, Q, T D Q, R, S, T 14 Sodium and aluminium are elements in Period 3 of the Periodic Table. Which statement concerning the co mpounds of sodium and aluminium is correct? A Both their chlorides give acid ic solutions when added to water. B Both their chlorides have similarly high boiling points. C Both their oxides give neutra l solutions when added to water. D Both their oxides react with hydrochloric acid. 15 The hexa-aquairon(III) ion, [Fe(H2O)6]3+, hydrolyses as shown. [Fe(H2O)6]3+(aq) [Fe(H2O)5(OH)]2+(aq) + H+(aq) Which of the following statements is correct? A The hydrolysis is favoured by low pH values. B The iron undergoes a change in