Why is oxalic acid called ethane-dioic acid

[ritwik06]

Why is oxalic acid called ethane-dioic acid even if it has nothing else but 2 carboxylic group??

 

[bomba923]

By convention, IUPAC nomenclature takes all carbons into consideration.
Carboxylic acids are nothing special //

For example, oxalic acid is a dicarboxylic acid containing two carbons;
hence, it is (systematically) named "ethanedioic acid" by IUPAC convention
(hyphenation is not required here).

Similarly,
malonic acid is "propanedioic acid",
succinic acid is "butanedioic acid",
glutaric acid is "pentanedioic acid",
adipic acid is "hexanedioic acid",
pimelic acid is "heptanedioic acid",
suberic acid is "octanedioic acid",
azelaic acid is "nonanedioic acid",
sebacic acid is "decanedioic acid",

..and so on...