Alcohols

Alcohols contain the hydroxyl (-OH) functional group. They are named by replacing final e of the parent alkane by -ol. Alcohols are soluble in water because they can form hydrogen bonds with water molecules.

1. Methanol (CH3OH)

Methanol is also called wood alcohol because it was earlier obtained by heating wood in the absence of air. It is prepared by heating carbon monoxide and hydrogen under pressure and by using a catalyst.

CO (g) + 2H2 (g) → CH3OH (g)

The reaction at 400°C, 200-300 atm; ZnO/Cr2O3 catalyst.

It has many industrial uses. It is used in the synthesis of acetic acid and many adhesives, fibers and plastics. It is also used as an additive to petrol and also as a fuel.

2. Ethanol (C2H5OH)

Ethanol is present in beer, wine and medicines. It is produced by the fermentation of carbohydrates such as glucose and starch present in grapes, barley. The reaction is catalyzed by the enzymes present in yeast.

C6H12O6 (aq) + Yeast → 2CH3CH2OH (aq) + 2CO2 (g)

It is used as solvent for organic compounds. It is also used as sprit (95% Ethanol).