Practical investigations
Read our general notes on Risk Assessment
I am looking at determining the alcohol content of wine by using a colorimeter on known ethanol solutions with potassium dichromate(VI), silver nitrate and sulphuric acid to produce a calibration curve followed by the same procedure with your unknown alcohol content, however potassium dichromate(VI) is a possible carcinogen and I was wondering if this was necessary in the solution and if so if there is something that is less expensive to dispose of that could be used instead?
Your question concerns the toxicity of potassium dichromate(VI).
Solid dichromates are highly toxic, being described as oxidising, dangerous to the environment, category 2 carcinogens and category 2 mutagens. This is why solid potassium dichromate must be handled using gloves and preferably when using its solutions too. However, in your titrations, relatively dilute solutions of dichromate(VI) e.g. less than 0.1 molar, are far safer to handle providing sensible precautions are taken. Given the hazards associated with solid potassium dichromate(VI) you may not be allowed to make up the solution yourself.
Always carry out a risk assessment before starting practical work, and check with your teacher. In this case even more than usual, ensure that your teacher knows exactly what practical work is proposed, and do not start it until you have permission to do so. Never work unsupervised.
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, 4 ratings so far
, rated at 
updated: 02 February 2006
