STRUCTURES OF ALCOHOLS, CARBOXYLIC ACIDS AND ESTERS
Organic molecules form the basis of living things and all contain carbon atoms. Carbon atoms bond covalently to each other to form the backbone of many series of organic molecules. Series of molecules that have a general formula are called homologous series. The alkanes and the alkenes are two homologous series made of only carbon and hydrogen atoms.
Alcohols contain the functional group -O-H. If one hydrogen atom from each alkane is replaced with an -O-H group, we get a homologous series of alcohols. The first three members of the alcohol series are methanol, ethanol and propanol. The structural formula shows which atoms are bonded to each carbon atom and the functional group. The structural formula of ethanol is CH3CH2OH.
Carboxylic acids have the functional group -COOH. The first three members of the carboxylic acids are methanoic acid, ethanoic acid and propanoic acid. Their structural formulae are HCOOH, CH3COOH and CH3CH2COOH.
Esters have the functional group -COO-. If the H atom in the -COOH group of a carboxylic acid is replaced by a hydrocarbon group, the compound is an ester. Ethyl ethanoate has the structural formula CH3COOCH2CH3.
PROPERTIES AND USES OF ALCOHOLS
Alcohols with smaller molecules, such as methanol, ethanol and propanol, mix well with water and produce neutral solutions. Many organic substances dissolve in alcohols and this makes them useful solvents. Ethanol is the main alcohol in wine, beer and other alcoholic drinks.
Alcohols burn in air…