6 th Year Chemistry Higher Level Sinéad Nolan. Volumetric Analysis

Transcription

1 6 th Year Chemistry Higher Level Sinéad Nolan Volumetric Analysis No part of this publication may be copied, reproduced or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without prior written permission from The Dublin School of Grinds. Ref: 6/che/h/sn/volumetric analysis

2 EASTER REVISION COURSES Looking to maximise your CAO points? Easter is well known as a time for students to vastly improve on the points that they received in their mock exams. To help students take advantage of this valuable time, The Dublin School of Grinds is running intensive exam-focused Easter Revision Courses. Each course runs for five days (90 minutes per day). The focus of these courses is to maximise students CAO points. Special offer: Buy 1st course and get 2nd course free. To avail of this offer, early booking is required as courses were fully booked last year. What do students get at these courses? EASTER REVISION COURSE FEES: PRICE TOTAL SAVINGS 1st Course nd Course FREE rd Course th Course th Course th Course ,075 7th Course ,270 8th Course ,465 9th Course ,660 NOTE: Any bookings for Junior Cert courses will also receive a weekly grind in one subject for the rest of the academic year, free of charge. This offer applies to 3rd and 2nd year students ONLY. FREE DAILY BUS SERVICE For full information on our Easter bus service, see 3 pages ahead minutes of intensive tuition per day for five days, with Ireland s leading teachers. Oral Preparation Courses 99 Comprehensive study notes. Separate to the Easter Revision Courses, The Dublin School of Grinds is also running Oral Preparation Courses. With the Oral marking component of the Leaving Certificate worth up to 40%, it is of paramount importance that students are fully prepared for these examinations. These courses will show students how to lead the Examiner towards topics that the student is prepared in. This will provide students with the confidence they need to perform at their peak. 99 A focus on simple shortcuts to raise students grades and exploit the critically important marking scheme. 99 Access to a free supervised study room. 99 Access to food and beverage facilities. NOTE: These courses are built on the fact that there are certain predicable trends that appear and reoccur over and over again in the State Examinations. ORAL PREPARATION COURSE FEES: PRICE To book, call us on or book online at TOTAL SAVINGS 1st Oral Course nd Oral Course

3 Timetable An extensive range of course options are available over a two-week period to cater for students timetable needs. Courses are held over the following weeks:»» Monday 21st March Friday 25th March 2016»» Monday 28th March Friday 1st April 2016 All Easter Revision Courses take place in The Talbot Hotel, Stillorgan (formerly known as The Stillorgan Park Hotel). 6th Year Easter Revision Courses SUBJECT LEVEL DATES TIME Accounting H Monday 21 st March Friday 25 th March 8:00am - 9:30am Agricultural Science H Monday 28 th March Friday 1 st April 2:00pm - 3:30pm Applied Maths H Monday 28 th March Friday 1 st April 8:00am - 9:30am Art History H Monday 28 th March Friday 1 April 8:00am - 9:30am Biology Course A* H Monday 21 st March Friday 25 th March 8:00am - 9:30am Biology Course A* H Monday 21 st March Friday 25 th March 12:00pm - 1:30pm Biology Course A* H Monday 28 th March Friday 1 st April 10:00am - 11:30am Biology Course B* H Monday 21 st March Friday 25 th March 10:00am - 11:30am Biology Course B* H Monday 21 st March Friday 25 th March 2:00pm - 3:30pm Biology Course B* H Monday 28 th March Friday 1 st April 8:00am - 9:30am Business H Monday 21 st March Friday 25 th March 12:00pm - 1:30pm Business H Monday 28 th March Friday 1 st April 8:00am - 9:30am Chemistry Course A* H Monday 28 th March Friday 1 st April 12:00pm - 1:30pm Chemistry Course B* H Monday 28 th March Friday 1 st April 2:00pm - 3:30pm Classical Studies H Monday 21 st March Friday 25 th March 8:00am - 9:30am Economics H Monday 21 st March Friday 25 th March 8:00am - 9:30am Economics H Monday 28 th March Friday 1 st April 10:00am - 11:30am English Paper 1* H Monday 21 st March Friday 25 th March 12:00pm - 1:30pm English Paper 2* H Monday 21 st March Friday 25 th March 10:00am - 11:30am English Paper 2* H Monday 21 st March Friday 25 th March 2:00pm - 3:30pm English Paper 2* H Monday 28 th March Friday 1 st April 10:00am - 11:30am English Paper 2* H Monday 28 th March Friday 1 st April 12:00pm - 1:30pm French H Monday 21 st March Friday 25 th March 10:00am - 11:30am French H Monday 28 th March Friday 1 st April 8:00am - 9:30am Geography H Monday 28 th March Friday 1 st April 8:00am - 9:30am Geography H Monday 28 th March Friday 1 st April 10:00am - 11:30am German H Monday 21 st March Friday 25 th March 10:00am - 11:30am History (Europe)* H Monday 21 st March Friday 25 th March 2:00pm - 3:30pm History (Ireland)* H Monday 21 st March Friday 25 th March 12:00pm - 1:30pm Home Economics H Monday 21 st March Friday 25 th March 10:00am - 11:30am Irish H Monday 21 st March Friday 25 th March 10:00am - 11:30am Irish H Monday 28 th March Friday 1 st April 12:00pm - 1:30pm Maths Paper 1* H Monday 21 st March Friday 25 th March 8:00am - 9:30am Maths Paper 1* H Monday 21 st March Friday 25 th March 12:00pm - 1:30pm Maths Paper 1* H Monday 28 th March Friday 1 st April 10:00am - 11:30am Maths Paper 1* H Monday 28 th March Friday 1 st April 2:00pm - 3:30pm Maths Paper 2* H Monday 21 st March Friday 25 th March 10:00am - 11:30am Maths Paper 2* H Monday 21 st March Friday 25 th March 2:00pm - 3:30pm Maths Paper 2* H Monday 28 th March Friday 1 st April 12:00pm - 1:30pm Maths Paper 2* H Monday 28 th March Friday 1 st April 4:00pm - 5:30pm Maths O Monday 21 st March Friday 25 th March 8:00am - 9:30am Maths O Monday 28 th March Friday 1 st April 12:00pm - 1:30pm Physics H Monday 28 th March Friday 1 st April 10:00am - 11:30am Spanish H Monday 21 st March Friday 25 th March 2:00pm - 3:30pm Spanish H Monday 28 th March Friday 1 st April 10:00am - 11:30am * Due to large course content, these subjects have been divided into two courses. For a full list of topics covered in these courses, please see 3 pages ahead. 6th Year Oral Preparation Courses SUBJECT LEVEL DATES TIME French H Sunday 20 th March 10:00am - 2:00pm German H Saturday 26 th March 10:00am - 2:00pm Irish H Saturday 26 th March 10:00am - 2:00pm Spanish H Saturday 19 th March 1:00pm - 5:00pm 5th Year Easter Revision Courses SUBJECT LEVEL DATES TIME Maths H Monday 28 th March Friday 1 st April 8:00am - 9:30am English H Monday 28 th March Friday 1 st April 4:00pm - 5:30pm Note: 5th year students are welcome to attend any 6th year course as part of our buy 1 get 1 free offer. 3rd Year Easter Revision Courses SUBJECT LEVEL DATES TIME Business Studies H Monday 28 th March Friday 1 st April 8:00am - 9:30am English H Monday 21 st March Friday 25 th March 8:00am - 9:30am English H Monday 28 th March Friday 1 st April 2:00pm - 3:30pm French H Monday 28 th March Friday 1 st April 12:00pm - 1:30pm Geography H Monday 28 th March Friday 1 st April 12:00pm - 1:30pm German H Monday 21 st March Friday 25 th March 8:00am - 9:30am History H Monday 21 st March Friday 25 th March 4:00pm - 5:30pm Irish H Monday 28 th March Friday 1 st April 2:00pm - 3:30pm Maths H Monday 21 st March Friday 25 th March 10:00am - 11:30am Maths H Monday 21 st March Friday 25 th March 12:00pm - 1:30pm Maths H Monday 28 th March Friday 1 st April 10:00am - 11:30am Maths O Monday 28 th March Friday 1 st April 12:00pm - 1:30pm Science H Monday 28 th March Friday 1 st April 2:00pm - 3:30pm Science H Monday 21 st March Friday 25 th March 2:00pm - 3:30pm Spanish H Monday 21 st March Friday 25 th March 12:00pm - 1:30pm 2nd Year Easter Revision Courses SUBJECT LEVEL DATES TIME Maths H Monday 21 st March Friday 25 th March 2:00pm - 3:30pm BUY 1ST COURSE GET 2ND COURSE FREE! NOTE: Any bookings for Junior Cert courses will also receive a weekly grind in one subject for the rest of the academic year, free of charge. This offer applies to 3rd and 2nd year students ONLY. BOOK EARLY TO AVAIL OF THE SPECIAL OFFER

4 Table of Contents Volumetric Analysis Procedures... 3 Determination of the amount of water of crystallisation in hydrated Na2CO Determination of the concentration of ethanoic acid in vinegar... 9 Estimation of iron in an iron tablet Iodine thiosulphate titration Determination of the percentage of hypochlorite in bleach Estimation of the total hardness of a water sample Estimation of dissolved oxygen by redox titration Past Exam Question 1 s Past Exam Solutions to Question 1 s... School of Grinds Page 2 Sinéad Nolan

5 Volumetric Analysis Procedures Primary standard pure / stable / anhydrous (not hydrated) / no water loss (no efflorescence) / not deliquescent / not hygroscopic /does not sublime / high molecular (molar) mass (Mr) from which solutions of known concentration (molarity) can be made / no need to standardise by titration / water soluble NB Primary standard for acid-base reactions = anhydrous sodium carbonate (Na 2 CO 3 ) [Allow (3) for sodium carbonate.] [OTHER POSSIBILITY: sodium tetraborate (disodium tetraborate] Primary standard for redox reactions = ammonium iron(ii) sulphate A standard solution is a solution whose concentration (molarity) is known A standardised solution is a solution whose concentration (molarity) known (found, got, etc.) by another titration (colorimetry, u.v. spectroscopy) Making up a solution starting with a solid solute rinse from clock glass into beaker containing deionised water // stir // dissolve // pour (add) through funnel into volumetric flask // add rinsings of beaker // add deionised water until bottom of meniscus on (level with) mark / read at eye level // stopper and invert* several times [* Do not allow shake for invert School of Grinds Page 3 Sinéad Nolan

6 Making up a solution with iron tablets tablets crushed with mortar and pestle // washed into beaker // stirred to dissolve // transferred into flask using funnel / glass rod // rinsings of beaker added to flask // flask on level surface / mark at eye-level // add drop-by-drop / add using dropper (pipette, wash bottle) / top up carefully // until bottom of meniscus level with mark // invert / mix / shake [ swirl not acceptable] Diluting a solution of bleach or vinegar pipette (burette) vinegar/bleach (3) can be shown on diagram into volumetric flask (3) can be shown with diagram provided line on neck present add deionised water (3) when near mark, add dropwise (using dropper/pipette/wash bottle) / until bottom of meniscus on (at) mark / read bottom of meniscus Procedure for preparing the burette rinse with deionised water rinse with reagent (solution) clamp vertically use funnel when adding reagent / remove funnel after filling open tap to fill below tap (tip, jet, nozzle) / remove air bubbles [Allow tap is full ] set bottom of meniscus on mark / read bottom of School of Grinds Page 4 Sinéad Nolan

7 Importance of filling the part below the tap air will be displaced by the solution (reagent) / some of measured volume replaces air / some of measured volume not delivered / some of measured volume goes to fill space / causes (gives) wrong (inaccurate, too high, too low) reading (result, titre) / air will be displaced (removed, got rid of) during the titration / will be filled during the titration / affects result / burette only works properly when it (part below tap) is full / burette designed to work properly when it (part below tap) is full / distorts result (reading) Description of how the level of the liquid in the burette was adjusted to the zero mark fill above mark and adjust with tap / fill to below mark and add dropwise Procedure for preparing the pipette rinse with water followed by the solution it is going to contain // fill pipette using a pipette filler to above the mark (graduation line) // adjust to have bottom of meniscus on mark / read at eye level (vertically) remove droplets adhering to outside // drain under gravity into titration flask // touch tip of pipette against side of flask to add droplet adhering to outside tip // do not blow out drop inside pipette Importance of using a pipette filler safety / avoid solution getting into mouth / hygiene Explanation of operations involving the conical flask and its contents during the titration swirl to mix // allow time after addition from burette for reaction // On white surface // Wash down sides with deionised water (NB this does not affect number of mols of reactants in the School of Grinds Page 5 Sinéad Nolan

8 Importance of placing the conical flask on a white tile so that colour-change (end-point) clearer (more easily seen) Precautions (and explanation of how this precaution would have contributed to the accuracy of the titration result) that should have been taken as the end point of the titration was approached. Precaution Explanation add drop by drop (slowly) add dropwise so that end point will be precisely (accurately) detected (correct end point not passed) / one drop of solution would change colour near end point wash down inner sides of conical flask wash sides so that all reagent(s) (acid) in the reaction mixture swirl (shake) flask contents swirl to ensure thorough mixing of School of Grinds Page 6 Sinéad Nolan

9 Determination of the amount of water of crystallisation in hydrated Na 2 CO 3 (2006) 1Na2CO3 = 2HCl M x 25 1 = M = 0.11x x x 1 2 x 25 (i) M = mol L 1 (molarity of the Na2CO3 solution) x 106 (Mr of Na2CO3) (ii) = g L 1 (concentration of the Na2CO3 solution in g L 1 ) 2 (solution only made up to 500 cm 3 ) = g of Na2CO3 in 500 cm 3 Mass of water of crystallization in the crystals = mass of crystals mass of Na2CO3 in 500 cm 3 = = g % by mass of water of crystallisation = 3 mass of water in 500 cm of the solution total mass of the crystals = x = 62.9 % (% by mass of water of crystallisation in crystalline Na2CO3) : (divide by Mr) : : (divide by smallest number) 1 : School of Grinds Page 7 Sinéad Nolan

10 Notes Indicator: methyl orange Colour change at the end-point: yellow (base) to pink (acid) Example of a strong acid weak base titration Methyl orange suitable as an indicator as the ph at the end point passes through the indicator range Not more than 1 2 drops of indicator should be used as indicators themselves are weak acids or weak bases and may affect titration results if added in larger School of Grinds Page 8 Sinéad Nolan

11 Determination of the concentration of ethanoic acid in vinegar (2008) 1CH3COOH = 1NaOH M x = M = 0.1x x 25 x 1 1 x M = 0.11 mol L 1 (molarity of the diluted vinegar) x 60 (Mr of CH3COOH) = 6.6 g L 1 (concentration of the diluted vinegar in g L 1 ) x 10 (dilution factor 25 cm 3 to 250 cm 3 ) = 66 g L 1 (concentration of the original vinegar in g L 1 ) x 10 (g L 1 to g 100 cm 3 = % (w/v)) = 6.6 % (w/v) (concentration of original vinegar in % School of Grinds Page 9 Sinéad Nolan

12 Notes The vinegar is diluted because it is too concentrated and there would have been a very large volume of NaOH needed to get a reasonable titration and also it would have required a very concentrated solution of NaOH for neutralisation Indicator: phenolphthalein Colour change at the end-point: pink (base) to colourless (acid) Example of a weak acid strong base titration Phenolphthalein suitable as an indicator as the ph at the end point passes through the indicator range Ethanol in white wine is oxidised to ethanoic acid in vinegar Methanoic acid is the acid which occurs in nettles and stinging ants Benzoic acid and it s salts are used as food preservatives, disinfectants, antiseptics, biocides and fungicides Not more than 1 2 drops of indicator should be used as indicators themselves are weak acids or weak bases and may affect titration results if added in larger School of Grinds Page 10 Sinéad Nolan

13 Estimation of iron in an iron tablet (2009) 5Fe 2+ = 1MnO4 - M x 25 5 = M = 0.1 x x x 5 1 x 25 (i) M = mol L 1 (molarity of the Fe 2+ solution) 4 (solution only made up to 250 cm 3 ) = mol 250 cm 3 x 56 (Ar of Fe) (ii) = g 250 cm 3 (total mass of iron in 250 cm 3 of the solution) 5 x = g (mass of the 5 tablets) % by mass of iron in the tablets = 3 mass of iron in 250 cm of the solution total mass of the tablets = x (iii) = 32% (% by mass of iron in the School of Grinds Page 11 Sinéad Nolan

14 Notes KMnO4 is a secondary standard as it decomposes in strong sunlight and so must be standardised immediately prior to use. KMnO4 is an oxidising agent and is easily reduced. It does not dissolve easily in water. The titre reading is taken from the top of the meniscus when KMnO4 is in the burette as the bottom of the meniscus is difficult to see due to the opaque nature of the KMnO4 Iron tablets are prescribed to prevent anaemia H2SO4 added when making up tablet solution to prevent Fe 2+ being oxidised to Fe 3+ by oxygen in the air H2SO4 added before each titration to ensure complete conversion of MnO4 - to Mn 2+ and to prevent formation of Mn 4+, a dirty brown precipitate Neither HCl or HNO3 can be used to acidify the solution in the conical flask as the Cl - ions in the HCl would be oxidised to produce Cl2 which is poisonous, and HNO3 is a strong oxidising agent itself and will take part in the reaction Self indicated: no indicator required Colour change at the end-point: colourless to first permanent pink colour Reaction is autocatalysed, i.e. Mn2+ which is a product of the reaction catalyses reaction. Rate of reaction increases as reaction School of Grinds Page 12 Sinéad Nolan

15 Iodine thiosulphate titration (2007) 2S2O3 = 1I2 M x 20 2 = M = 0.05 x x 25 x 2 1 x 20 M = mol L 1 (molarity of the Na2S2O3.5H2O solution) x 248 (Mr of Na2S2O3.5H2O) = 31 g L 1 (concentration of crystalline Na2S2O3.5H2O in g L 1 School of Grinds Page 13 Sinéad Nolan

16 Notes KI is added to bring/keep the I2 in solution; pure I2 is insoluble in water, as water is polar and I2 is non-polar and hence cannot form hydrogen bonds with water molecules Indicator: starch Colour change at the end-point: blue-black to colourless Colour changes from the start of the titration: KMnO4 + KI / H2SO4 Na2S2O3 + starch + Na2S2O3 purple reddy/ straw blueblack brown yellow colourless Starch is only added once the solution turns straw yellow. If the starch was added before this stage then the blue-black complex that is formed is too concentrated and too stable to decompose fast enough to give an accurate School of Grinds Page 14 Sinéad Nolan

17 Determination of the percentage of hypochlorite in bleach (2011) 1ClO - = 1I2 1I2 = 2S2O3 1ClO - = 2S2O3 M x 25 1 (i) (ii) = M = 0.1 x x 16.1x 1 2 x 25 M = mol L 1 (molarity of the diluted bleach) x 20 (dilution factor 25 cm 3 to 500 cm 3 ) = mol L 1 (molarity of the original bleach) x 74.5 (Mr of NaClO) (i) = g L 1 (concentration of NaClO in g L 1 ) (i) 10 (g L 1 to g 100 cm 3 = % (w/v)) = % (w/v) (concentration of NaClO in % School of Grinds Page 15 Sinéad Nolan

18 Notes The bleach is diluted because it is too concentrated and there would have been a very large volume of Na2S2O3 needed to get a reasonable titration KI added for two reasons (i) to ensure all the bleach reacted and that the maximum amount of iodine was liberated and (ii) to bring/keep the I2 in solution; pure I2 is insoluble in water, as water is polar and I2 is non-polar and hence cannot form hydrogen bonds with water molecules Indicator: starch Colour change at the end-point: blue-black to colourless Colour changes from the start of the titration: bleach + KI / H2SO4 Na2S2O3 + starch + Na2S2O3 colourless reddy/ straw blueblack brown yellow colourless Starch is only added once the solution turns straw yellow. If the starch was added before this stage then the blue-black complex that is formed is too concentrated and too stable to decompose fast enough to give an accurate School of Grinds Page 16 Sinéad Nolan

19 Estimation of the total hardness of a water sample (2010) 1M 2+ = H2Y 2- M x 50 1 = M = 0.01x x 9.20 x 1 1 x 50 (i) M = mol L 1 (moles per litre of calcium and magnesium ions (M 2+ )) (ii) (iii) x 100 (Mr of CaCO3) = g L 1 (grams per litre expressed in terms of CaCO3) x 1000 (g L 1 mg L 1 ppm) = 184 ppm (ppm in terms of School of Grinds Page 17 Sinéad Nolan

20 Notes EDTA = ethylene diamine tetraacetic acid Indicator: Eriochrome Black T or Solochrome Black T, a grey-blue solid Colour change: wine-red to blue Complexiometric titration EDTA forms a complex with the Ca 2+ and Mg 2+ ions that are present in the hard water Indicator complexes with Ca 2+ and Mg 2+ ions at the start of the experiment = wine-red colour Add the EDTA, Ca 2+ and Mg 2+ ions will form a complex with the EDTA Indicator without the Ca 2+ and Mg 2+ ions = blue colour Buffer ph = 10 is added as the indicator only works accurately at phs greater than 9 Not using a buffer may lead to a poor endpoint, incomplete complexing or EDTA complexing with other ions The general purpose of buffers is to resist changes in ph or to stabilize the ph EDTA is stored in a plastic bottle as it may extract metal ions from glass if left in a glass container for long periods of School of Grinds Page 18 Sinéad Nolan

21 Estimation of dissolved oxygen by redox titration 1O2 = 4Mn(OH)3 4Mn(OH)3 = 2I2 2I2 = 4S2O3 1O 2 = 4S2O3 M x = M = 0.02 x x 5.7 x 1 4 x 100 M = mol L 1 (molarity of the dissolved oxygen in the water) x 32 (Mr of O2) = g L 1 (concentration of the dissolved oxygen in the water in g L 1 ) x 1000 (g L 1 mg L 1 ppm) = 9.12 ppm (concentration of the dissolved oxygen in the water in ppm) NB 1:4 ratio if asked to calculate O2 concentration directly; 1:2 ratio if asked to calculate I2 concentration School of Grinds Page 19 Sinéad Nolan

22 Notes Indicator: starch Colour change at the end-point: blue-black to colourless Colour changes from the start of the titration: white ppt brown ppt reddy/brown straw yellow blue-black colourless Starch is only added once the solution turns straw yellow. If the starch was added before this stage then the blue-black complex that is formed is too concentrated and too stable to decompose fast enough to give an accurate end-point The following precautions should be observed when collecting water for B.O.D. analysis (i) fill the bottle under the surface of the water to prevent atmospheric oxygen being trapped and, thus, giving an artificially high oxygen level (ii) fill the bottle completely to ensure that no air is trapped between the top of the water and the stopper of the bottle and (iii) the second bottle is stored in the dark for 5 days at 20 o C to prevent photosynthesis leading to an increased oxygen content or to prevent respiration which will lead to a decrease in the oxygen content Concentrated solutions of MnSO4 and alkaline KI are used to minimise the amount of the water sample that is displaced, to minimise the change in the oxygen dissolved in the sample and to ensure that a small volume of solution supplies an excess The additions were made well under the level of the water, using a dropper, making sure not to bubble air into the water in the process Water samples that may have high B.O.D.s should be diluted by a fixed amount with well-oxygenated water in order to ensure that dissolved oxygen will be present during the 5 day period and that a measurable amount of oxygen will be present at the end of the test period It can be concluded that no dissolved oxygen is present had a white precipitate been observed instead of the brown precipitate after the first two additions of reagents to the bottle filled with river water? Kits, designed for use in the field, allow the dissolved oxygen concentration to be measured immediately on collection of the sample. The immediate determination of dissolved oxygen is considered best practice as biochemical (biological) reactions (photosynthesis, respiration, metabolism) may occur which will alter the dissolved oxygen School of Grinds Page 20 Sinéad Nolan

23 Past Exam Question 1 s LC 2015 Question 1 School of Grinds Page 21 Sinéad Nolan

24 Solution (cont School of Grinds Page 22 Sinéad Nolan

25 LC 2014 Question 1 School of Grinds Page 23 Sinéad Nolan

26 Solution (cont School of Grinds Page 24 Sinéad Nolan

27 LC 2013 Question 1 School of Grinds Page 25 Sinéad Nolan

28 Solution (cont School of Grinds Page 26 Sinéad Nolan

29 LC 2012 Question 1 School of Grinds Page 27 Sinéad Nolan

30 Solution (cont School of Grinds Page 28 Sinéad Nolan

31 LC 2011 Question 1 School of Grinds Page 29 Sinéad Nolan

32 Solution (cont School of Grinds Page 30 Sinéad Nolan

33 LC 2010 Question 1 School of Grinds Page 31 Sinéad Nolan

34 Solution (cont School of Grinds Page 32 Sinéad Nolan

35 LC 2009 Question 1 School of Grinds Page 33 Sinéad Nolan

36 Solution (cont School of Grinds Page 34 Sinéad Nolan

37 LC 2008 Question 1 School of Grinds Page 35 Sinéad Nolan

38 Solution (cont School of Grinds Page 36 Sinéad Nolan

39 LC 2007 Question 1 School of Grinds Page 37 Sinéad Nolan

40 Solution (cont School of Grinds Page 38 Sinéad Nolan

41 LC 2006 Question 1 School of Grinds Page 39 Sinéad Nolan

42 Solution (cont School of Grinds Page 40 Sinéad Nolan

43 LC 2005 Question 1 School of Grinds Page 41 Sinéad Nolan

44 Solution (cont School of Grinds Page 42 Sinéad Nolan

45 LC 2004 Question 1 School of Grinds Page 43 Sinéad Nolan

46 Solution (cont School of Grinds Page 44 Sinéad Nolan

47 LC 2003 Question 1 School of Grinds Page 45 Sinéad Nolan

48 Solution (cont School of Grinds Page 46 Sinéad Nolan

49 LC 2002 Question 1 School of Grinds Page 47 Sinéad Nolan

50 Solution (cont School of Grinds Page 48 Sinéad Nolan

51 Past Exam Solutions to Question 1 s LC 2015 Question 1 School of Grinds Page 49 Sinéad Nolan

52 LC 2014 Question 1 School of Grinds Page 50 Sinéad Nolan

53 LC 2013 Question 1 School of Grinds Page 51 Sinéad Nolan

54 LC 2012 Question 1 School of Grinds Page 52 Sinéad Nolan

55 LC 2011 Question 1 School of Grinds Page 53 Sinéad Nolan

56 LC 2010 Question 1 School of Grinds Page 54 Sinéad Nolan

57 LC 2009 Question 1 School of Grinds Page 55 Sinéad Nolan

58 LC 2008 Question 1 School of Grinds Page 56 Sinéad Nolan

59 LC 2007 Question 1 School of Grinds Page 57 Sinéad Nolan

60 LC 2006 Question 1 School of Grinds Page 58 Sinéad Nolan

61 LC 2005 Question 1 School of Grinds Page 59 Sinéad Nolan

62 LC 2004 Question 1 School of Grinds Page 60 Sinéad Nolan

63 LC 2003 Question 1 School of Grinds Page 61 Sinéad Nolan

64 LC 2002 Question 1 School of Grinds Page 62 Sinéad Nolan