The document discusses esters and their properties. Key points include: 1. Esters are chemicals that often smell nice and are used in perfumes. They can be extracted from plants or made synthetically. 2. Esters are made by reacting a carboxylic acid with an alcohol. 3. For perfumes to work, the ester molecules must have weak intermolecular forces so they evaporate easily at body temperature and diffuse to smell receptors.