The IUPAC name of oxalic acid is:

The chemical formula of oxalic acid is (COOH)₂ or COOH-COOH.

According to the IUPAC nomenclature rule, the root word 'eth' should be used for oxalic acid as it contains two carbon atoms.

As two COOH groups (functional groups) are present, the suffix "dioic acid" should be used.

So, the IUPAC name of oxalic acid is "ethanedioic acid."

Oxalic acid is the common name or trivial name of ethanedioic acid.