Hydrolysis of Halides
Both primary and secondary alcohols can be produced by boiling an aqueous solution of alkali hydroxides such as potassium hydroxide or sodium hydroxide with a suitable alkyl halide such as bromomethane, colour ethane, etc. The reaction is a nucleophilic substitution reaction. Below is an example of the preparation of alcohol using this method:
R-X + NaOH —-> R-OH + NaX
CH₄ + NaCl —-> CH₃OH + NaCl
Preparation of Alcohols
When one or more hydroxyl groups (-OH) are directly attached to the hydrocarbon chain then the compound formed is known as alcohol. Some examples of alcohol are phenol, methanol and ethanol.
Alcohols can be classified into various types based on the number of hydroxyl groups in the structure of the compound. These types are:
- Monohydric Alcohol: Alcohols containing only one hydroxyl group are called monohydric alcohols. For example, ethanol and methanol
- Dihydric Alcohol: Alcohols containing two hydroxyl groups are called monohydric alcohols. Example, 1,2-Ethanol.
- Trihydric Alcohol: Alcohols containing three hydroxyl groups are called monohydric alcohols. Example 1,2,3-Propanol.
- Polyhydric Alcohol: Alcohols containing more than 3 hydroxyl groups are called monohydric alcohols. Example, 1,2,3,4-Pentanol.