IJC H2 Chem 2012 Prelim P2 QP

INNOVA JUNIOR COLLEGE JC2 PRELIMINARY EXAMINATION 2 in preparation for General Certificate of Education Advanced Level Higher 2 CANDIDATE NAME CLASS INDEX NUMBER CHEMISTRY Paper 2 Structured Questions Candidates answer on the Question Paper Additional Materials: Data Booklet 9647/02 11 September 2012 2 hours READ THESE INSTRUCTIONS FIRST Write your index number, name and civics group. Write in dark blue or black pen. You may use pencil for any diagrams, graphs or rough working. Do not use staples, paper clips, highlighters, glue or correction fluid. Answer all questions in the space provided. A Data Booklet is provided. You are advised to show all working in calculations. You are reminded of the need for good English and clear presentation in your answers. You are reminded of the need for good handwriting. Your final answers should be in 3 significant figures. You may use a calculator. The number of marks is given in brackets [ ] at the end of each question or part question. At the end of the examination, fasten all your work securely together. For Examiner’s Use Section A 1 12 2 12 3 15 4 12 5 11 6 10 Significant figures Handwriting Total 72 This document consists of 18 printed pages. Innova Junior College [Turn over

2 PRELIM 2  INNOVA 9647/02/2012 [Turn over For Examiner’s Use Answer ALL questions on the spaces provided. 1 Planning (P) A student was given 50 cm 3 of three acidic solutions labelled X, Y and Z. She was asked to provide the identities of them by conducting a simple experiment. The identities of the three solutions are 1 mol dm -3 ethanoic acid, CH3COOH 1 mol dm-3 hydrochloric acid, HCl 2 mol dm-3 hydrochloric acid, HCl Her teacher advised her to measure the temperature change of the reactions and calculate the enthalpy change of neutralisation of an acid and base reaction. The student is also provided with 200 cm 3 of 1 mol dm-3 sodium hydroxide, NaOH. The student let the volume ratio of each of the three solutions to sodium hydroxide be 1:1. She tested the experiment and realised that with this volume ratio, she is unable to differentiate the different concentrations of hydrochloric acid. (a) Construct balanced equations for the reactions between the given acids and base. [1] (b) The following table shows the volumes used by the student. Explain, with the aid of calculation, why the student’s experiments will not aid the differentiation of the different concentrations of hydrochloric acid. Experiment Volume of 1 mol dm -3 NaOH / cm3 Volume of 1 mol dm-3 HCl / cm3 Volume of 2 mol dm-3 HCl / cm3 1 50 50 2 50 50 ........................................................................................................................... ........................................................................................................................... ........................................................................................................................... ........................................................................................................................... …………………………………………………………………………………………….…[2]

3 PRELIM 2  INNOVA 9647/02/2012 [Turn over For Examiner’s Use (c) Write a plan which will allow an identification of the three solutions to be made. You may use the reagents and apparatus normally found in a school or college laboratory. However, you are not provided with an indicator. In your plan you should give essential details, including quantities, of the identification procedure. ........................................................................................................................... ........................................................................................................................... ........................................................................................................................... ........................................................................................................................... ........................................................................................................................... ........................................................................................................................... ........................................................................................................................... ........................................................................................................................... ........................................................................................................................... ........................................................................................................................... ........................................................................................................................... ........................................................................................................................... ........................................................................................................................... ........................................................................................................................... ........................................................................................................................... ........................................................................................................................... ........................................................................................................................... ........................................................................................................................... ........................................................................................................................... ........................................................................................................................... ........................................................................................................................... ………………………………………………………………………………………………[6]

4 PRELIM 2  INNOVA 9647/02/2012 [Turn over For Examiner’s Use (d) Explain how you can make use of your experimental data to identify the three solutions. ........................................................................................................................... ........................................................................................................................... ........................................................................................................................... ........................................................................................................................... …………………………………………………………………………………………….…[2] (e) Discuss one possible source of error in conducting your experiment and suggest improvement to produce a more reliable result. ........................................................................................................................... ........................................................................................................................... …………………………………………………………………………………………..…...[1] [Total: 12]

5 PRELIM 2  INNOVA 9647/02/