Concept: Alcohols are important organic compounds containing the hydroxyl group ( ). Ethyl alcohol (ethanol) and methyl alcohol (methanol) are widely used in industries due to their solvent properties and ability to undergo chemical reactions.
Preparation of Ethyl Alcohol (Ethanol):
(1) By Fermentation of Sugars: Sugars like glucose are fermented using yeast under anaerobic conditions. Steps:
Preparation of sugar solution (molasses or fruit juice)
Addition of yeast
Fermentation at
Distillation to obtain pure ethanol
(2) By Hydration of Ethene (Industrial Method): Ethene reacts with steam in presence of acid catalyst. Industrial Uses of Ethyl Alcohol:
As a Solvent: Used in perfumes, paints, varnishes, and pharmaceuticals.
As Fuel: Used as biofuel and blended with petrol (gasohol).
In Chemical Industry: Used in manufacture of acetic acid, ether, esters, and other organic compounds.
Alternative: Methyl Alcohol (Methanol): Preparation: Produced by destructive distillation of wood or by catalytic reaction of carbon monoxide and hydrogen. Uses:
Fuel and antifreeze
Solvent in industries
Manufacture of formaldehyde and plastics