ortho acid

ortho acid

[′ȯr·thō ′as·əd] (organic chemistry) Aromatic acid with a carboxyl group in the ortho position (1,2 position). Organic acid with one added molecule of water in chemical combination; for example, HC(OH)3, orthoformic acid, in contrast to HCOOH, formic acid; H3PO4(P2O5·3H2O), orthophosphoric acid, in contrast to the less hydrated form, metaphosphoric acid, HPO3(P2O5·H2O).