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Science fair

Proposal question: Which catalyst is most effective in producing the purest aspirin when synthesized with salicylic acid and acetic anhydride to produce aspirin and acetic acid?

The catalyst, glacial acetic acid, will be the most efficient in yielding the purest aspirin because of its chemical properties of C2H4O2. The process of synthesizing aspirin is an esterification reaction, meaning that the phenol group of the salicylic acid reacts with an acid anhydride, the functional group of acetic anhydride, to make ester. During the synthesis, the H+ ions, given off by the catalyst, are being recycled. So the more hydrogen plus ions, the more pure the end product will be.


Materials and vendors:
1. Balance, weigh boats, scoops –Ms.O’Neill
2. Pipets and pumps–Ms.O’Neill
3. Ethanol, 95%–Ms.O’Neill
4. Filter paper, 12.5 cm–Ms.O’Neill
5. Erlenmeyer flasks, Pyrex, 250mL, and rubber stopper –Ms.O’Neill 6. Hood, chemical fume –Ms.O’Neill
7. Hydrochloric acid, 12 M –Ms.O’Neill
8. Glacial Acetic acid- Ms. O’Neill
9. Sulfuric acid, 18 M- Ms. O’Neill
10. Glacial acetic acid- ms. O’Neill
11. NaOH, 0.1 M–Ms.O’Neill
12. Salicylic acid –Ms.O’Neill
13. Tubes, glass, 13x100 mm and racks –Ms.O’Neill
14. Plug caps for 13x100 mm tubes –Ms.O’Neill
15. Ferric nitrate, nonahydrate, 1% –Ms.O’Neill
16. Micropipet, P-1000 and tips –Ms.O’Neill
17. Glass rods–Ms.O’Neill
18. Hot Plate –Ms.O’Neill
19. Buchner funnel –Ms.O’Neill
20. Deionized water –Ms.O’Neill


Part I:
Obtain four test tubes, cleanses and label each (test tube 1, 2, 3, and 4). Individually weigh out 1 g of salicylic acid and 2 mL of acetic anhydride and place them in the test tubes. Mix thoroughly with a glass rod until as much of the solid has dissolved as possible. Add two drops of catalyst (test tube 1 with sulfuric acid, test tube 2 with glacial acetic acid, test tube 3 with hydrochloric acid, and test tube 4 with no catalyst). Heat the reaction in a warm water bath of about 40 Celsius for 15 minutes. Once the time is up, place the test tubes inside the ice bath, a mixture of water and ice, for 5 minutes. While it is cooling, prepare four mixtures of 5 g ice and 5 mL of cold water. After 5 minutes, add in the ice/water mixture and let it sit inside the ice bath for another 10 minutes. Observe any changes to the solutions. Stir the test tubes with a glass rod to speed up the crystallization process. Obtain 4 pieces of filter paper and label each with an assigned number of 1, 2, 3, or 4 with a pencil. Measure the weight of each individual filter paper and record it.

Once the 10 minutes is up, use a Buchner funnel and filter off the crystals (place the filter paper on top of the Buchner funnel and let the water drain out until there is only crystals left over). Place the filter paper on a plate form and wash each reaction test tube with two-5mL portions of ice water (Pour it directly over the crystals on the filter paper). Set each filter paper aside and let it dry.

Part II:
Weigh out the air-dried filter papers, watch glass, and product. Record the mass of each and calculate the mass of the individual product.

Heat some water on a hot plate and put 2.5 mL of ethanol into a test tube (total of 4 test tubes) and warm it in the hot water bath. Be sure to label the test tubes 1, 2, 3, and 4. Once the ethanol is heated, dissolve the aspirin samples in the 2.5 mL of the warm ethanol. Warm this at the same time you warm 5 mL of deionized water (total of 4 tubes). When the aspirin-ethanol mixture starts to boil remove it from the hot water bath and add the warm deionized water directly to the test tubes. Make sure everything has dissolved. Let the solutions cool at room temperature for 10 minutes and then place them into an ice bath. Stir the content with a glass rod. Wait until crystals form then filter out the crystals using a...
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