|1.||Also called: orthophosphorous acid, Systematic name: phosphoric acid a white or yellowish hygroscopic crystalline dibasic acid. Formula: H3PO3|
|2.||any oxyacid of phosphorus containing less oxygen than the corresponding phosphoric acid|
|phosphorous acid (fŏs'fər-əs, fŏs-fôr'əs) Pronunciation Key
A white or yellowish crystalline solid used as a reducing agent. It is hygroscopic (easily absorbs moisture from the atmosphere). Chemical formula: H3PO3.
one of several oxygen acids of phosphorus, used as reducing agent in chemical analysis. It is a colourless or yellowish crystalline substance (melting point about 73 C, or 163 F) with a garliclike taste. An unstable compound that readily absorbs moisture, it is converted to phosphoric acid (H3PO4) in the presence of oxygen or when heated above 180 C (360 F). Phosphorous acid (H3PO3) forms salts called phosphites, also used as reducing agents. It is prepared by dissolving tetraphosphorus hexoxide (P4O6) or phosphorus trichloride (PCl3) in water.
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