Reactions of alcohols

Reactions of alcohols

• Alcohols undergo 3 important reactions:

• (a) Combustion

• (b) Oxidation

• (c) Esterification

Combustion of alcohols

• Alcohols burn in oxygen to produce carbon dioxide and water.

• C₂H₅OH + 3O₂ --> 2CO₂ + 3H₂O

Oxidation of alcohols

• Alcohols are oxidised to carboxylic acids.

• The number of carbon atoms remain the same in oxidation.

• CH₃CH₂OH + 2[O] --> CH₃COOH + H₂O

• The oxidation is carried out by using

• (i) oxygen

_• (ii) acidified K₂Cr₂O₇

_• (iii) acidified KMnO₄

Oxidation of alcohols

• During the oxidation:

– Acidified K₂Cr₂O₇ turns from orange to green

– acidified KMnO₄ is decolourised.

Esterification

• Alcohols react with organic acids to form esters. Esters are sweet fruity-smelling compounds.

• Word equation :

• Alcohol + carboxylic acid --> ester + water

Uses of ethanol

• As a solvent

• As a fuel

• As a constituent of wine and beer

• Human consumption of wine and beer can lead to alcohol addiction.

A model of an ethanol molecule

• Ethanol, C₂H₅OH, is used in beer making.