Dehydration of Alcohols
- Dehydration of alcohols is a chemical reaction in which an alcohol loses a molecule of water (H₂O) to form another compound.
- It usually occurs in the presence of a strong acid catalyst (like concentrated sulfuric acid or phosphoric acid) and requires heating.
Types of Dehydration
- Intramolecular Dehydration
- Water is removed within the same alcohol molecule.
- Produces an alkene.
- Example: Ethanol on dehydration gives ethene.
- Intermolecular Dehydration
- Water is removed from two molecules of alcohol.
- Produces an ether.
- Example: Ethanol molecules combine to form diethyl ether.
General Characteristics
- The ease of dehydration to alkenes follows the order: tertiary > secondary > primary alcohols.
- The reaction depends on temperature and catalyst used.
- Lower temperature (around 140 °C) favors ether formation.
- Higher temperature (around 170 °C) favors alkene formation.
In short: Dehydration of alcohols is the removal of water, giving either alkenes (intramolecular) or ethers (intermolecular) depending on the conditions.