Ethanol is the type of alcohol found in alcoholic drinks such as wine and beer. Its chemical formula is: C2H5OH. Glucose from plant material is converted into ethanol and carbon dioxide by fermentation.
The enzymes found in yeast (single-celled fungi) are the natural catalysts that can make this process happen. Here is the word equation: Sugar → Ethanol + Carbon Dioxide
Fermentation of glucose using yeast
You measure 15ml of yeast solution in a conical flask and add 25ml of sucrose solution. The yeast is used to act as a catalyst and therefore speed up the reaction. This solution is then placed into a beaker of warm water between 25-37 degrees Celsius. You then place a bung into the fermenting solution, and the delivery tube into a boiling tube of lime water. This is to show that CO₂ is present when the limewater turns cloudy, indicating that Ethanol is being formed. To make sure no CO₂ escaped the boiling tube, we filled the opening with cotton wool.
Percentages of various alcoholic drinks:
Many alcoholic drinks have different percentages of Ethanol meaning they will have a different effect on the consumer.
Percentages of Ethanol in:
Vodka – 35-40% (In the UK)
Beer – 4-5%
Cider – 5-8.5%
Wine – 9-14%
Fortified Wine – 18-22%
Whiskey – 40-46%
Ouzo – 37.5%+
Brandy – 40-60%
Liqueurs – 15-55%
Absinthe – 40-90%
Barley Wine – 8-15%
Health and Social issues involving alcohol
Alcohol consumption is linked to many harmful consequences for the individual drinker, the drinker’s immediate environment and society as a whole. Some social consequences are: traffic accidents, workplace-related problems, family and domestic problems, and interpersonal violence.
Heavy drinking at the workplace may potentially lower productivity. Sickness absence associated with harmful use of alcohol and alcohol dependence entails a