Alcohol

General FormulaCnH2n+1OH, n = 1, 2, 3, …….

Functional Group:

Hydroxyl

First 3 Members:

Chemical Properties:

1.      Alcohols are compounds in which one or more hydrogen atoms in an alkane have been replaced by an -OH group.

Naming Alcohols

  1. All alcohol members have a suffix ‘anol’. For example, methanol, ethanol, propanol ……
  2. The nomenclature of alcohol, like alkanes, is based on the number of carbon atoms in the molecule, but the suffix ‘ane’ in the nomenclature of alkanes is replaced with the suffix ‘anol’.
  3. The positions of the alkyl and hydroxyl groups that the attached to the carbon chain are shown by numbering the carbon atoms. The hydroxyl group must always get the smallest possible number.

Example 1

(Propan-2-ol)

Longest chain: 3 carbon (propanol)
Position of hydroxyl group: 2
Alkyl:

Example 2

(Pentan-1-ol)

Longest chain: 5 carbon (pentanol)
Position of hydroxyl group: 1
Alkyl: –

Example 3

(2-methylpropan-2-ol)

Longest chain: 3 carbon (propanol)
Position of hydroxyl group: 2
Alkyl: Methyl at 2nd carbon

Example 4

(3-methylbutan-1-ol)

Longest chain: 4 carbon (butanol)
Position of hydroxyl group: 1
Alkyl: Methyl at 3rd carbon

Example 5

(2,2-dimethylpropan-1-ol)

Longest chain: 3 carbon (propanol)
Position of hydroxyl group: 1
Alkyl: 2 Methyls, both at 2nd carbon

Uses of Alcohols

Alcohol can be used as

  1. beverage
  2. fuel
  3. solvent
  4. Antiseptic