
	Trending ▼ ICSE CBSE 10th ISC CBSE 12th CTET GATE UGC NET Vestibulares ResFinder

GCE MAY 2010 : (A2 3) Internal Assessment: Practical Examination2 - Revised

12 pages, 23 questions, 0 questions with responses, 0 total responses,

	gce	+Fave Message
	Profile Timeline Uploads Q & A

Home > gce >

Instantly get Model Answers to questions on this ResPaper. Try now!
NEW ResPaper Exclusive!

Formatting page ...

Sp N ec e ifi w ca tio n Centre Number 71 Candidate Number ADVANCED General Certificate of Education 2010 Chemistry Internal Assessment Practical Examination 2 AC232 Assessment Unit A2 3 [AC232] FRIDAY 21 MAY TIME 2 hours 30 minutes. INSTRUCTIONS TO CANDIDATES Write your Centre Number and Candidate Number in the spaces provided at the top of this page. Answer all three questions. Write your answers in the spaces provided. INFORMATION FOR CANDIDATES The total mark for this paper is 70. Questions 1 and 2 are practical exercises each worth 25 marks. Question 3 is a planning exercise worth 20 marks. Quality of written communication will be assessed in Question 3. You may not have access to notes, textbooks and other material to assist you. A Periodic Table of elements (including some data) is provided. For Examiner s use only Question Number 1 2 3 110065 Total Marks 6033 Marks Modera -tion Mark 1 Titration exercise Teacher Examiner Remark Mark Check An acidified solution of sodium iodate(V) acts as an oxidising agent. You are provided with: a solution of sodium iodate(V) of unknown concentration; four 20 cm3 portions of sulphuric acid; four 1.5 g samples of potassium iodide; sodium thiosulphate solution of concentration 0.05 mol dm 3; starch indicator. Assuming that all the apparatus is clean and dry, you are required to carry out a titration and use your results to calculate the concentration of sodium iodate(V). (a) Give details of the procedure you intend to use. ________________________________________________________ ________________________________________________________ ________________________________________________________ ________________________________________________________ ________________________________________________________ ________________________________________________________ ________________________________________________________ ________________________________________________________ ________________________________________________________ ________________________________________________________ ________________________________________________________ ________________________________________________________ ______________________________________________________ [6] 6033 2 [Turn over (b) Carry out your procedure. Present your results in a suitable table and calculate the average titre. Teacher Examiner Remark Mark Check [10] 6033 3 [[Turn over (c) (i) Calculate the number of moles of iodine liberated in the conical flask. Teacher Examiner Remark Mark Check ____________________________________________________ ____________________________________________________ ____________________________________________________ __________________________________________________ [2] (ii) Balance the following half-equation: IO3 + H+ I2 + H2O [2] (iii) Combine the reduction half-equation above with the following oxidation half-equation: 2 I I2 2e + __________________________________________________ [2] (iv) Calculate the concentration of the sodium iodate(V) solution in g dm 3. ____________________________________________________ ____________________________________________________ ____________________________________________________ ____________________________________________________ __________________________________________________ [3] 6033 4 [Turn over BLANK PAGE (Questions continue overleaf) 6033 5 [Turn over 2 Observation/deduction Teacher Examiner Remark Mark Check Safety goggles must be worn at all times and care should be exercised during this practical examination. (a) You are provided with a salt, labelled A. Carry out the following tests. Record your observations in the spaces below. Test Observations 1 Describe the appearance of A. [1] 2 Dissolve a spatula measure of A in approximately 50 cm3 of water. [1] 3 Add a few drops of barium chloride solution to 2 cm3 of the solution of A. [1] 4 Add a few drops of sodium hydroxide solution to 2 cm3 of the solution of A. [2] 5 In a fume cupboard, add excess concentrated ammonia solution dropwise, until present in excess, to 2 cm3 of the solution of A. [3] 6 Add approximately 8 cm3 of concentrated hydrochloric acid to 2 cm3 of the solution of A. [2] 6033 6 [Turn over Deduce the formulae of the complexes formed in: Teacher Examiner Remark Mark Check Test 2 _______________________________________________ [1] Test 5 _______________________________________________ [1] Test 6 _______________________________________________ [1] Deduce the name of compound A. _____________________________________________________ [2] (b) Compounds B and C have the molecular formula C3H6O. They produce an orange solid when reacted with 2,4-dinitrophenylhydrazine. Carry out the following test on B. A sample of C is not required. Record your observations in the space below. Test Observations Mix 1cm3 of Fehling s No.1 solution with an equal volume of Fehling s No. 2 solution. Add about 1cm3 of B and heat in a water bath for at least five minutes. [3] Deduce the structural formula of B _____________________________________________________ [1] Deduce the structural formula of C _____________________________________________________ [1] 6033 7 [[Turn over (c) Compounds D and E have the molecular formula C3H6O2. They both produce a triplet, quartet and singlet in their NMR spectra. Carry out the following test on D. A sample of E is not required. Record your observations in the space below. Test Teacher Examiner Remark Mark Check Observations Add a spatula measure of sodium carbonate to about 1cm3 of D in a test tube. [3] Deduce the structural formula of D _____________________________________________________ [1] Deduce the structural formula of E _____________________________________________________ [1] 6033 8 [Turn over BLANK PAGE (Questions continue overleaf) 6033 9 [Turn over Planning exercise 3 Teacher Examiner Remark Mark Check Preparation of butyl butanoate, CH3CH2CH2COOCH2CH2CH2CH3 Butyl butanoate is a liquid with a boiling point of 165 C and a density of 0.87 g cm 3. It may be prepared by reaction between butanoic acid and butan-1-ol using concentrated sulphuric acid as a catalyst. You are required to prepare 30 cm3 of pure butyl butanoate based on the mass of butanoic acid used. (a) Write an equation for the esterification. ______________________________________________________ [2] (b) Calculate the mass of butanoic acid needed assuming a 70% yield. ________________________________________________________ ________________________________________________________ ________________________________________________________ ______________________________________________________ [4] (c) The first stage produces a crude sample of the ester. Describe this procedure, including an explanation for any relevant safety precautions, apart from using safety glasses. ________________________________________________________ ________________________________________________________ ________________________________________________________ ________________________________________________________ ________________________________________________________ ______________________________________________________ [5] 6033 10 [Turn over (d) (i) Describe how the acid impurities are removed. Teacher Examiner Remark Mark Check _____________________________________________________ _____________________________________________________ _____________________________________________________ __________________________________________________ [3] (ii) How is the butyl butanoate dried? _____________________________________________________ __________________________________________________ [2] (iii) Describe how the butyl butanoate is further purified. _____________________________________________________ _____________________________________________________ __________________________________________________ [2] Quality of written communication [2] THIS IS THE END OF THE QUESTION PAPER 6033 11 [Turn over Permission to reproduce all copyright material has been applied for. In some cases, efforts to contact copyright holders may have been unsuccessful and CCEA will be happy to rectify any omissions of acknowledgement in future if notified. 110065

Formatting page ...

Additional Info : Gce Chemistry May 2010 Assessment Unit A2 3 Internal Assessment: Practical Examination 2
Tags : General Certificate of Education, A Level and AS Level, uk, council for the curriculum examinations and assessment, gce exam papers, gce a level and as level exam papers , gce past questions and answer, gce past question papers, ccea gce past papers, gce ccea past papers

gce chat

Horizontal lines at:
Guest Horizontal lines at:
AutoRM Data:
Box geometries: