Photo AI
Describe how you used yeast to produce alcohol (ethanol) - Leaving Cert Biology - Question c - 2008
Question c
Describe how you used yeast to produce alcohol (ethanol). Include a labelled diagram of the apparatus that you used. How did you show that alcohol had been produced... show full transcript
Worked Solution & Example Answer:Describe how you used yeast to produce alcohol (ethanol) - Leaving Cert Biology - Question c - 2008
Step 1
How did you show that alcohol had been produced?
Answer
To demonstrate that alcohol has been produced, various tests can be conducted:
-
Potassium Dichromate Test: Add acidified potassium dichromate solution to a small sample of the liquid. The initial orange colour of the potassium dichromate indicates the presence of ethanol, as it will change to green if alcohol is present due to the reduction of dichromate to chromium ions.
-
Iodoform Test: Add iodine solution in the presence of sodium hydroxide to the sample. If ethanol is present, this will produce a brownish-yellow colour, confirming the presence of alcohol.