Oxidation: The loss of electrons and gain in oxygen.
*complete combustion of ethanol:
Ethanol can be oxidised by the process of complete combustion as ethanol burns when heated in air or oxygen:
Ethanol + Oxygen → Carbon dioxide + water
C2H5OH 3O2 2CO2 3H2O
- The microbial oxidation of ethanol occurs once a bottle of wine is opened.
- This is caused by the bacteria in the air (acetobacter) using atmospheric oxygen from air to oxidise the ethanol in wine, producing a weak solution of ethanoic acid (also known as acetic acid):
Ethanol + Oxygen → Ethanoic Acid + Water
C2H5OH 3O2 CH3COOH 3H2O
So once a bottle of wine has been opened, it can quickly turn into vinegar due to the large number of bacteria in the air.
*Heating with potassium dichromate (vi) in dilute Sulfuric acid:
- Ethanol can be oxidised by heating it with an oxidising agent such as Potassium dichromate (vi) in dilute Sulphuric acid.
- The alcohol is oxidized to a carboxylic acid.
- If the oxidation occurs, then the orange solution containing the dichromate (vi) ions is reduced to a green solution containing chromium (ii) ions: