59. Alcohols

1. What are Alcohols?

Alcohols are a homologous series of organic compounds. They are structurally similar to alkanes but contain an -OH group (hydroxyl group) in place of one hydrogen atom.

• Naming: To name an alcohol, replace the final "-e" of the corresponding alkane with "-ol".

  • Methane → Methanol

  • Ethane → Ethanol

• General Formula: The general formula for alcohols is CnH2n+1OH.

• First Four Alcohols:

  • Methanol (CH3OH)

  • Ethanol (C2H5OH)

  • Propanol (C3H7OH)

  • Butanol (C4H9OH)

2. Properties of Alcohols

The first four alcohols in the series share several key chemical properties:

• Flammability: They are highly flammable and undergo complete combustion in air.

  • Reaction: Alcohol + Oxygen → Carbon Dioxide + Water

• Solubility: They are soluble in water and dissolve to form a neutral solution (pH 7).

• Oxidation: Alcohols can be oxidized to form carboxylic acids. For example, ethanol can be oxidized to ethanoic acid. These acids contain the functional group -COOH.

3. Uses of Alcohols

• Fuels: Because they release large amounts of energy when burned, they are commonly used as fuels (e.g., in spirit burners).

• Solvents: In industry, alcohols are often used as solvents because they can dissolve substances that water cannot, such as hydrocarbons, fats, and oils.

• Alcoholic Drinks: Ethanol is the specific alcohol found in alcoholic beverages.