Oxoacids (and its variants oxyacids, oxo acids, oxy-acids, oxiacids, oxacids) is a traditional name for any acid having oxygen in the acidic group. The term stands in contradistinction to `hydracids' (e.g.
HCl) lacking oxygen. The term oxoacid now refers to a compound which contains oxygen, at least one other element, and at least one hydrogen bound to oxygen, and which produces a conjugate base by loss of positive hydrogen ion(s) (hydrons). E.g.
P(OH)3,
RC(=O)OH,
HOSOH,
HOCl,
HON=O,
(HO)2SO2 ,
RP(=O)(OH)2.
See also: oxo carboxylic acids
Sources:
PAC, 1995, 67, 1307. 'Glossary of class names of organic compounds and reactivity intermediates based on structure (IUPAC Recommendations 1995)' on page 1355 (https://doi.org/10.1351/pac199567081307)
Red Book, 3rd ed., p. 123 (https://doi.org/10.1515/pac-2014-0718)