• synonyms

phosphorous acid

noun Chemistry.
  1. a colorless, crystalline, water-soluble acid of phosphorus, H3PO3, from which phosphites are derived.
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Origin of phosphorous acid

First recorded in 1785–95
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

British Dictionary definitions for phosphorous acid

phosphorous acid

  1. Also called: orthophosphorous acid a white or yellowish hygroscopic crystalline dibasic acid. Formula: H 3 PO 3Systematic name: phosphoric acid
  2. any oxyacid of phosphorus containing less oxygen than the corresponding phosphoric acid
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Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

phosphorous acid in Science

phosphorous acid

[fŏsfər-əs, fŏs-fôrəs]
  1. A white or yellowish crystalline solid used as a reducing agent. It is hygroscopic (easily absorbs moisture from the atmosphere). Chemical formula: H3PO3.
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The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.