The functional group present in an ester is
- A. COOR, formed by replacing the acidic hydrogen of a carboxylic acid
- B. OH attached to a benzene ring
- C. NH2 attached to a carbon chain
- D. a carbon to carbon triple bond
Explanation
An ester is formed when a carboxylic acid reacts with an alcohol, water being eliminated, and the resulting group is responsible for the pleasant fruity smells used in flavourings and perfumes. A hydroxyl on a benzene ring makes a phenol and an NH2 group makes an amine. Esterification is reversible and is catalysed by concentrated sulphuric acid.