Practical investigations
Read our general notes on Risk Assessment
I was going to check the purity of my aspirin by melting it and comparing its melting point with what it should be. I am however unsure how to melt an aspirin tablet, i.e. to get rid of filler etc.
300408
Corrie writes ....
You can check the purity of your aspirin by determining its melting point and comparing it with the value for pure aspirin from books - values range from 135 - 140oC. The reason for this rather wide range (melting points of pure susbtances should be sharp) is that aspirin starts to decompose at temperatures approaching its melting point.
As regards determining the melting point of aspirin in a tablet, you would have to separate out the pure aspirin first. Attempting to melt the tablet itself (after crushing it) would be pointless as it is likely to contain a variety of other substances, such as the fillers you suggest. There are problems doing this, which you can see discussed in an answer to an earlier FAQ.
Risk assessment
Before attempting any practical work based on the advice and suggestions on this website, you must do the following. Identify any hazards, assess the risks from these hazards, and then decide appropriate control measures to reduce the risks. You must have these approved by those in authority in your school or college laboratory. Do not rely on what is said on this website.
For further guidance see our tutorial on Risk Assessment.
back to Practical investigations
Rate this page or react
Share your views on this page, 0 ratings so far
updated: 01 May 2008
