IJC H2 CHEM P2 QN P

INNOVA JUNIOR COLLEGE JC2 PRELIMINARY EXAMINATIONS 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 14 September 2011 2 hour 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. This document consists of 18 printed pages and 2 blank pages. Innova Junior College [Turn over For Examiner’s Use Section A 1 12 2 15 3 12 4 9 5 13 6 11 Significant figures Handwriting Total 72

2 PRELIM 2  INNOVA 9647/02/2011 [Turn over For Examiner’s Use Answer ALL questions on the spaces provided. 1 You are given a number of different acids to investigate how the enthalpy change of neutralisation, ∆Hneutralisation, varies when the acids are neutralised with aqueous sodium hydroxide, NaOH. (a) (i) Hydrochloric acid, nitric acid and sulfuric acid are all strong acids. Predict how ∆H neutralisation values for these acids would compare with each other. ............................................................................................................................. ............................................................................................................................. (ii) Predict and explain how the expected ∆H neutralisation for a weak acid, such as ethanoic acid or ethanedioic acid, compares with that for hydrochloric acid. ............................................................................................................................. ............................................................................................................................. ............................................................................................................................. [2] (b) (i) Draw and label a diagram of the apparatus you would use to determine the temperature change, ∆T, when each of the acids reacts with 30.0 cm 3 of 2.0 mol dm-3 aqueous sodium hydroxide. Any experimental method that is normally carried out in a college laboratory may be used.

3 PRELIM 2  INNOVA 9647/02/2011 [Turn over For Examiner’s Use (ii) Identify one possible source of error in the experiment and state how you would minimise the effect. ............................................................................................................................. ............................................................................................................................. ............................................................................................................................. ............................................................................................................................. [3] (c) In each experiment, 30.0 cm 3 of 2.0 mol dm-3 aqueous NaOH is to be used. Suggest appropriate volumes for each of the acids to be used in the individual experiments. Acid Volume/ cm 3 Concentration/ mol dm -3 Hydrochloric HCl 2.0 Ethanedioic (CO 2H)2 1.0 [1] (d) Ethanedioic acid is a hydrated crystalline solid, (CO2H)2.2H2O. Outline how you would prepare 100 cm 3 of 1 mol dm-3 solution of ethanedioic acid. In your answer, you should show how you determine the initial mass of ethanedioic acid to be used. [Ar: C, 12.0; H, 1.0; O, 16.0] [You are given more writing space on the following page] ...................................................................................................................................... ...................................................................................................................................... ...................................................................................................................................... ...................................................................................................................................... ...................................................................................................................................... ...................................................................................................................................... ...................................................................................................................................... ...................................................................................................................................... ...................................................................................................................................... ...................................................................................................................................... ...................................................................................................................................... ...................................................................................................................................... ...................................................................................................................................... ......................................................................................................................................

4 PRELIM 2  INNOVA 9647/02/2011 [Turn over For Examiner’s Use ...................................................................................................................................... ...................................................................................................................................... ...................................................................................................................................... ...................................................................................................................................... ...................................................................................................................................... [4] (e) Using the volume and concentration from (c) and ∆T to represent the temperature change, derive a mathematical expression for the enthalpy change of neutralisation of sodium hydroxide with hydrochloric acid. [4.3 J of heat energy raise the temperature of 1 cm 3 of any solution by 1 °C] [1] (f) Suggest what modification you could make to your experimental procedure to ensure complete neutralisation of the acid. ...................................................................................................................................... ..............................................................................................