Extended Essays 2021

7. The beaker was then placed on top of the hotplate set at ‘high’ heat, and with the retort stand and clamp it was ensured that the glass thermometer was submerged into the liquid. 8. The solution was then heated to evaporate the excess methanol for at least half an hour (Making sure that the temperature was past the boiling point of methanol is 64.7 ℃ (National Library of Medicine, 2021)) until two district layers were present in the mixture 9. The solution was then transferred into a separatory funnel and was allowed to cool 10. 250 3 of cold deionized water was used to rinse the round bottom flask, transferring any of the remaining solution into separatory funnel 11. After about 5 minutes when two layers were able to be distinctly seen, the lower layer was separated carefully into another 100 3 beaker, while the upper aqueous layer was discarded into a 250 3 waste beaker 12. 5g of magnesium salicylate was then measured with the weighing boat on the electronic balance 13. The synthesized solution was then dried by transferring it into the 50 3 volumetric flask with 5g of magnesium sulphate 14. Once the flask was capped, the solution was shaken k for about 5 minutes, and then left to stand for at an hour with occasional shaking 15. Another 100 3 beaker was then weighed and tared on the electronic balance 16. The methyl salicylate solution was then filtered using the retort stand, glass funnel and filter paper into the tared 100 3 beaker 17. The synthesised methyl salicylate was then collected into the tared beaker and weighed on the electronic balance 18. The UV Spectrophotometer was calibrated with a solution of ethanol 19. 2 3 of the synthesised methyl salicylate, 1 3 of the ferric chloride solution and 7 3 of ethanol were measured with separate 1 0 3 measuring cylinders and then added to the 100 3

beaker where the solution was stirred with the glass rod 20. A glass cuvette was then filled ¾ with the solution

21. The cuvette was placed inside the spectrophotometer as the absorbance value was recorded 22. Steps 2-19 were repeated for a total of 3 trials for the rest of the reflux solutions (2, 3, 4 & 5-hours)

Appendix #8: List of all chemicals & apparatus  50g salicylic acid, solid (0.2mol)  1,200 3 Methanol, pure liquid (2.1mol)  120 3 Conc. sulphuric acid (~18M)  75g magnesium sulphate (anhydrous), solid (0.04mol)  300 3 Ethanol, pure liquid (100%)  3,750 3 deionized water  1 x Condenser  1 x Heating mantle  1 x 250 3 round-bottom flask  1 x separatory funnel  7 x 10 3 graduated measuring cylinder  2 x 100 3 graduated measuring cylinder  Safety clip  1 x 250 3 graduated measuring cylinder

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2 x water hose

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1 x retort stand

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2 x clamp

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15 x filter paper sheets (No. 103) 2 x 100 3 volumetric flask

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3 x 100 3 beaker 2 x 250 3 beaker

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2 x weighing boat

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1 x glass funnel

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Electronic balance

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4 x glass cuvette

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UV spectrophotometer

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5 x pipettes

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Porcelain chips

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Glass rod

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Glass thermometer

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Tape & pen (for labelling)

15 3 Methyl Salicylate, pure liquid (100%)

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19