32.1 Alcohols
- Syllabus
- 9701–2028–2029
- Topic
- 32.1
- Level
- A2
Learning objectives
Ethanoyl chloride and ethanol form ethyl ethanoate and HCl
An alcohol reacts rapidly with an acyl chloride at room temperature to form an ester and hydrogen chloride. For the required example, ethanol supplies the ethyl group and ethanoyl chloride supplies the ethanoate part of the ester name.
CHX3COCl+CHX3CHX2OHCHX3COOCHX2CHX3+HCl
| Reactant | Structural contribution to the ester |
|---|---|
| ethanol, CH3CH2OH | ethyl group attached through oxygen: CH3CH2O- |
| ethanoyl chloride, CH3COCl | ethanoate acyl part: CH3CO- |
| combined ester | ethyl ethanoate, CH3COOCH2CH3 |
The reaction is vigorous and the hydrogen chloride by-product is seen as steamy white fumes in moist air. Unlike esterification with a carboxylic acid, this acyl-chloride route does not need concentrated sulfuric acid catalyst and is not presented as a reversible equilibrium.
The by-product is HCl, not water. This card describes the overall change; the detailed addition-elimination electron mechanism belongs to section 33.3 rather than this alcohol outcome.