Nature's Chemistry: Alcohols

Nature’s Chemistry: Alcohols

Overview of Alcohols

• Alcohols are a family of organic compounds that contain a hydroxyl functional group, -OH.
• They have a general formula of CnH2n+1OH, where n is the number of carbon atoms.

Classification of Alcohols

• Alcohols are classified as primary, secondary, or tertiary based on the position of the OH group.
• Primary alcohols have the OH group attached to a carbon atom that is only attached to one other carbon atom.
• Secondary alcohols have the OH group attached to a carbon atom that is attached to two other carbon atoms.
• Tertiary alcohols have the OH group attached to a carbon atom that is attached to three other carbon atoms.

Properties of Alcohols

• The intermolecular forces in alcohols are hydrogen bonds which are stronger than the ones in similar sized alkanes, making alcohols have higher boiling points.
• There is limited solubility of alcohols in water, which decreases as the size and length of the carbon chain increases.

Reactions of Alcohols

• Alcohols undergo combustion to produce carbon dioxide and water.
• Alcohols can be oxidised; primary alcohols can be fully oxidised to carboxylic acids, secondary alcohols can be oxidised to ketones, but tertiary alcohols cannot be oxidised.
• Alcohols can be dehydrated in the presence of a catalyst to form alkenes.
• Alcohols participate in esterification reactions, combining with carboxylic acids to produce esters and water.

Uses of Alcohols

• Lower members of the alcohol family are used in drinks due to their psychoactive properties and characteristic tastes.
• Alcohols are widely used in the pharmaceutical industry for the preparation of medicines, antiseptics, and disinfectants.
• They are used as solvents in perfumes, paints, and varnishes because they dissolve organic compounds well.
• Alcohols can be converted into biofuels, providing a renewable source of energy.