orthophosphorous acid

[ awr-thuh-fos-fer-uh s, awr-thoh-fos-fawr-uh s, -fohr- ]
/ ˈɔr θəˈfɒs fər əs, ˌɔr θoʊ fɒsˈfɔr əs, -ˈfoʊr- /

noun Chemistry.

a white to yellowish, crystalline, hygroscopic, water-soluble solid, H3PO3, used chiefly in the synthesis of phosphites.

Origin of orthophosphorous acid

British Dictionary definitions for orthophosphorous acid

orthophosphorous acid
/ (ˌɔːθəʊˈfɒsfərəs) /

noun

a white or yellowish hygroscopic crystalline dibasic acid. Formula: H 3 PO 3 Also called: phosphorous acid