Formation of ethanol

• Alcohols are a family of organic compounds containing carbon , hydrogen and oxygen.

• The general formula of alcohols is C_nH_2n+1OH (n = 1, 2, 3, 4…)

• The reacting group (or functional group) is the hydroxyl group, -OH.

• The names of an alcohol end with –ol.

• Propanol has 2 isomers.

Formation of ethanol

• Ethanol is obtained by

• (a) fermentation

• (b) catalytic addition of steam to ethene

• (a) Fermentation breaks down the sugar into ethanol and carbon dioxide. Yeast is used as a catalyst.

_• C₆H₁₂O₆ --> 2C₂H₅OH + 2CO₂

sugar ethanol

Temperature of 37^oC is used. Temperature is important in fermentation.

• (b) Addition of steam to ethene at high temperature (300^oC) and pressure (67 atm) produces ethanol. Phosphoric acid is used as a catalyst.

• CH₂=CH₂ + H₂O --> CH₃-CH₂OH