1. Redox reactions

2. Redox reactions of primary alcohols
Primary alcohols react with oxidising agents such as potassium manganate(VII) or sodium dichromate(VI), forming the corresponding aldehyde
For example, ethanol reacts forming ethanal
Ethanal is also formed in the metabolism of ethanol in the human body

3. Reaction of ethanol with sodium dichromate(VI)

4. Reaction of ethanol with sodium dichromate(VI)
This reaction is used in the preparation of ethanal
Reaction conditions: heat, excess ethanol, acidified sodium dichromate(VI) solution
The aldehyde is distilled off as it is formed in order to prevent further oxidation to ethanoic acid

5. Preparation of ethanal

6. Oxidation of primary alcohols
Primary alcohols such as ethanol are oxidised to the corresponding aldehydes, which can be further oxidised to the corresponding carboxylic acids.

7. Oxidation of ethanol

8. Reaction of ethanol with sodium dichromate(VI)
This reaction is used in the preparation of ethanoic acid
Reaction conditions: heat, excess acidified sodium dichromate(VI) solution
The reaction mixture is refluxed in order to bring about oxidation to ethanoic acid

9. Preparation of ethanoic acid
Reflux followed by Distillation

10. Oxidation of secondary alcohols
Secondary alcohols such as propan-2-ol are oxidised to the corresponding ketones, such as propanone
Unlike aldehydes, ketones are not easily oxidised, and so no further oxidation takes place

11. Oxidation of propan-2-ol

12. Combustion of organic compounds
Most organic compounds burn in air, forming carbon dioxide and water
The structure of the compounds’ molecules is completely destroyed, with the carbon and hydrogen atoms in each molecule being oxidised
Combustion is exothermic, and ethanol is used as a fuel where it can be produced cheaply

13. Non-flammable organic compounds
Fully halogenated alkanes such as bromochlorodifluoromethane are non-flammable
Because of this they can be used in fire extinguishers and as flame retardants
For environmental reasons, the use of many of these substances is being phased out

14. Reduction of aldehydes and ketones
Aldehydes and ketones can be reduced to the corresponding alcohols, using hydrogen passed over the heated surface of a nickel catalyst
For example, ethanal is reduced to ethanol

15. Reduction of ethanal to ethanol

16. Reduction of propanone to propan-2-ol