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Introduction

Making Aspirin Aim: to be able to make aspirin Equipment: * Vacuum Filtration – Buchner funnel and flask * Balance * Air Condenser * Conical Flask * Beaker * Measuring Cylinder * Spatula * Petri Dish * Hot water bath – approx. 60oC * Hydroxybenzoic Acid * Ethanoic Anhydride * Sulphuric Acid * Distilled Water Method: * Collect all the equipment, using a measuring balance weigh out 5.0g of 2-hydrobenzoic acid in a conical flask. Then add 7cm3 of ethanoic acid anhydride and also add three drops of concentrated sulphuric acid. * At the top of the conical flask fit the air condenser and mix together the reagents and then add to a water bath with a temperature between 50- 60 °C for 15 minutes. * After you have taken the conical flask out of the water bath then run it under cold water, remember not to remove the air condenser. * Next add 75cm3 of distilled water, and then using a glass rod stir well. * Then using a separating funnel adds filter paper to the top of the vacuum filter and then pours the solution into the Buchner funnel. ...read more.

Middle

This procedure of crystal formation helps to clean the substance. This is because the structure of crystal is reliant on on the form of the lattice pattern. Re-crystallisation depends on on alteration in solubility of substances so the impurities substances crystal out first so the rest can re-crystallise. Aspirin is less soluble then the impurity, so when adding cold water to it the saturated point reduces. As this reduces this shows that no more is able to dissolve allowing white solids to form. These solids form they crystallise so more products comes out allowing more crystallisation to occur leaving behind the impurities. Melting point results table: Test tubes Temperature C⦠1st try 132 C⦠2nd try 128 C⦠3rd try 130 C⦠Average of the temperature: 132 + 128 + 130 = 390 C⦠390C⦠= 130C⦠3 AVERAGE = 130 C⦠The melting point of pure aspirin: The melting point of aspirin is between138-140 Câ¦, my results were lower than that, this is because in my aspirin they were impurities, these impurities will lowered the melting point of my aspirin therefore making my melting point of the aspirin that I made about 130Câ¦. ...read more.

Conclusion

and put it on the TLC Plate and let it dry, you place the dots with the capillary tube four times and see the colour, then get a beaker and add ethanol acetate into the beaker and wait until the four dots go up on the TLC Plate and change colour and then make a mark. Results:- From my results I got two different results this is because, I used two different aspirins, a commercial aspirin which affected the results because in the commercial aspirin, chemicals where added and in the original aspirin I got normal results. Evaluation: While I was doing experiments in found it easy to work with a partner, the method was easy to set up, I found it difficult to understand the concept of some of the techniques used. Io found it easy to put the equipment away and use it, I had no problem. But because of the science laboratory, we didn?t have all of the resources that we needed so we didn?t make pure aspirin, if I had to do the experiments again I would make sure that I have all the resources that I need to make pure aspirin. ...read more.

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