Name of fun. group → carboxyl group
General formula → CnH2n+1 (n = 1,2,3,...)
Definition :
The derivatives of alkanes obtained by replacing one hydrogen atom of alkanes with one carboxyl group with general formula R- COOH or CnH2n+1 COOH (n = 1,2,3,...) called mono carboxylic acid.
Nomenclature :
1) Common name system :
I) The common names of carboxylic acids are derived from their sources.
II) Use the prefixes m, Iso & neo whenever needed.
IUPAC system :
Rule No. 1:
Select the longest carbon chain containing - COOH group.
Count the number of carbon atoms in normal chain along with carbon atom of - COOH group .
Find the name of parent alkane.
Replace ending 'e' of alkane with 'oic acid' term, Thus it becomes alkanoic acid.
Rule No. 2:
Start numbering to normal chain carbon atom from carbon atom of - COOH group.
Rule No. 3:
Give the name and position of branched groups.
Rule No. 4:
It acid contains 2,3&4 similar branched groups, use the prefixes di, tri & tetra respectively.
Rule No. 5:
It acid contains dissimilar branched groups suggest their names by alphabetical oders.
| SL. No | Formula | Common name | IUPAC name | ||
| 1 |  |
Formic acid [Formica = Redant] |
methanoic acid | ||
| 2 |  |
Acetic acid [Acetum = vinegar] |
ethanoic acid | ||
| 3 |  |
Propionic acid [Propiona = first fat] |
Propanoic acid | ||
| 4 |  |
n-Butyric acid [Butyrum = Butter] |
butanoic acid | ||
| 5 |  |
IsoButyric acid [above source] |
2-methylpropanoic acid | ||
| 6 |  |
n-valeric acid [Valerian tree] |
pentanoic acid | ||
| 7 |  |
Isovaleric acid [above source] |
3−methylbutanoic acid | ||
| 8 |  |
neovaleric acid | 2,2−dimethylpropanoic acid | ||
| 9 |  |
n-caproic acid [caprum = Intestine of goat] |
hexanoic acid |