A2 Chemistry
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i want to ask what might the remainder of the aspirin tablets be made of?
the tablets are reacted with NAOH
Corrie writes...
Here's an earlier reply to a similar question by Igloo which contains the information you want>
'In order to check the purity, you could measure the melting point, but you’re correct, you would certainly need to remove the “filler material” first. Since the latter is largely a mixture of insoluble matter such as cellulose, silica and starches you could try grinding the tablets into water, using suction filtration, and then using crystallisation to isolate the “aspirin”. However, I am by no means certain that this would be successful since some of the starch is likely to accompany the aspirin into the filtrate. Also this method assumes that the aspirin and the most likely contaminant – salicylic acid – will both crystallise out together, and this is by no means inevitable, since I suspect that the latter is far more water-soluble.'
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updated: 01 October 2007
