phosphorous acid

American  

noun

Chemistry.

1. a colorless, crystalline, water-soluble acid of phosphorus, H 3 PO 3 , from which phosphites are derived.

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phosphorous acid British  

noun

1. Systematic name: phosphoric acid.  Also called: orthophosphorous acid.  a white or yellowish hygroscopic crystalline dibasic acid. Formula: H 3 PO 3

2. any oxyacid of phosphorus containing less oxygen than the corresponding phosphoric acid

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phosphorous acid Scientific  

/ fŏs′fər-əs,fŏs-fôr′əs /

1. A white or yellowish crystalline solid used as a reducing agent. It is hygroscopic (easily absorbs moisture from the atmosphere). Chemical formula: H ₃ PO ₃ .

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Etymology

Origin of phosphorous acid

First recorded in 1785–95

Example Sentences

See Examples For:

phosphorous acid

The best method for preparing pure phosphorous acid is by hydrolyzing phosphorus trichloride:

From Textbooks ● Feb. 14, 2019

When sufficient water evaporates, white crystals of phosphorous acid will appear upon cooling.

From Textbooks ● Feb. 14, 2019

Like most other nonmetal halides, both phosphorus chlorides react with an excess of water and yield hydrogen chloride and an oxyacid: PCl3 yields phosphorous acid H3PO3 and PCl5 yields phosphoric acid, H3PO4.

From Textbooks ● Feb. 14, 2019

Write equations showing the stepwise ionization of phosphorous acid.

From Textbooks ● Feb. 14, 2019

Bodies absorbing oxygen, as sulphurous acid, phosphorous acid, and alcohols, decolorize it; under the influence of oxygen its color is restored.

From The Art of Perfumery And Methods of Obtaining the Odors of Plants by Piesse, George William Septimus