Practical investigations
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I am doing my A2 practical investigation for OCR Salters on the amount of iron in iron tablets. I have decided to use three different methods and compare different brands of iron tablets. I have already identified 2 methods - titration and colorimetry. However, I cannot think of the third and last one. Also what are the three best brands of iron tablets to use and compare as I have heard that not all iron tablets work in the titration experiment?
Ulex writes
I presume your ‘titration’ is with potassium manganate(VII). This works well but there is another one which you might be able to try: titration with potassium dichromate(VI). You will need to look up the details of this because it is rather more involved than the usual one. You need to bear in mind that there are safety issues with potassium dichromate(VI) and also with the indicator barium diphenylamine sulphonate which you will probably use.
I always used ‘ferrous sulphate’ tablets from Boots. I would be inclined to avoid preparations which have iron(II) (ferrous) sulphate in them but also other active ingredients as these may well interfere with the analysis. (Unless, of course, you want to discuss the reasons for such interference, which would be an interesting thing to do.)
Always carry out a risk assessment and check with your teacher before starting any practical work.
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.
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updated: 28 January 2007
