Ethanol (C2H5OH) is the type of alcohol found in alcoholic drinks such as wine and beer. It is also used as fuel for cars.
- Reacting ethene with steam (hydration):
A mixture of ethene and steam is passed over a hot catalyst of phosphoric acid at a temperature of 300°c and 60-70 atmospheres of pressure and is then condensed into a liquid for use:
Ethene + Water → Ethanol
C2H4 H2O C2H5OH
Equation showing the reaction that takes place between ethene and steam
- Fermentation of glucose:
Sugar or starch is dissolved in water and yeast is added to be fermented at 30°C with the absence of oxygen for a few days. Yeast contains zymase enzymes (biological catalysts) break down starch or sugar to glucose. The yeast respires anaerobically using the glucose to form to ethanol and carbon dioxide:
Glucose → Ethanol + Carbon Dioxide
C6H12O6 2C2H5OH 2CO2
Equation showing the fermentation of glucose by anaerobic respiration
Fermentation: a chemical process in which microorganisms such as yeast act on carbohydrates to produce ethanol and carbon dioxide. Sugars and starch are examples of carbohydrates.