Practical investigations
Read our general notes on Risk Assessment
I am starting to do a practical investigation into vinegars and one of the tasks is to remove the colouring from vinegars. I am at the moment trying to remove the colouring by using activated charcoal but this is proving long and is not amazingly successful.
Igloo says
It is essential to remove the colour from the vinegar otherwise the indicator colour change at the end point will be masked.
The use of activated charcoal can work very well; here are some ideas to try out:
[1] Always use a fresh sample of activated charcoal. If yours doesn’t work, try another from a newly purchased bottle. Make sure that it is “activated” charcoal you are using. Ordinary powdered charcoal simply won’t do!
[2] Once you have added the charcoal, stir vigorously with a glass rod, and allow the mixture to stand for at least 5 minutes before filtering. There is no need to heat it.
[3] Perhaps you are using too much charcoal at a time, which means that the mixture filters very slowly. Try using less charcoal, perhaps two small lots in succession.
[4] Use a Buchner flask, i.e. filter under reduced pressure. This will speed up the removal of the charcoal.
Always carry out a risk assessment before starting any practical work, and check with your teacher.
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: 29 November 2004
