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13. CARBOXYLIC ACIDS eLearn.Punjab

13.2 NOMENCLATURE OF CARBOXYLIC ACIDS

The aliphatic monocarboxylic acids are commonly called fatty acids because
higher members of this series such as palmitic acid (C15H31COOH), stearic
acid (C17H35COOH), etc. are obtained by the hydrolysis of fats and oils.
The aliphatic monocarboxylic acids may be given common names or IUPAC
names.

13.2.1 Common or Trivial names
The common names of carboxylic acids were derived from the source from which
they are isolated. The irritation caused by an ant bite is due to formic acid (Latin
word formica, ant). It was first isolated by the distillation of red ants. Similarly
acetic acid was first isolated from vinegar and butyric acid was named after
butyrum means butter.

13.2.2 The IUPAC Nomenclature

The IUPAC names of saturated monocarboxylic acids are alkanoic acids. These
are derived from the names of the alkanes containing the same number
of carbon atoms as the acid. The ending “e” of the alkane name is dropped
and suffix-oic acid is added. Thus acetic acid gets the name ethanoicaeid.

The position of substituents are indicated by Arabic numerals with the carboxyl
group given number 1 as shown below:

The common and IUPAC names of the some common monocarboxylic acids
are given in the table below.

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