- a colorless, crystalline, water-soluble acid of phosphorus, H3PO3, from which phosphites are derived.
Origin of phosphorous acid
First recorded in 1785–95
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
- Also called: orthophosphorous acid a white or yellowish hygroscopic crystalline dibasic acid. Formula: H 3 PO 3Systematic name: phosphoric acid
- any oxyacid of phosphorus containing less oxygen than the corresponding phosphoric acid
- A white or yellowish crystalline solid used as a reducing agent. It is hygroscopic (easily absorbs moisture from the atmosphere). Chemical formula: H3PO3.