What is Phosphorous acid?
'''Phosphorous acid''' is a [[chemical compound]]. It is an [[acid]]. Its chemical formula is H<sub>3</sub>PO<sub>3</sub>. It contains [[hydrogen]] and [[phosphite]] [[ion]]s. ==Properties== [[File:Phosphonic-acid-3D-balls.png|thumb|Phosphorous acid]] It is a white solid. It absorbs water. It is a strong [[reducing agent]]. It can be [[deprotonation|deprotonated]] twice. When it is heated, it turns into [[phosphoric acid]] and [[phosphine]]. It is toxic. [[Salt]]s of phosphorous acid is called phosphites. It reacts with [[mercury(II) chloride]] to make [[mercury(I) chloride]]. If it still is kept, it reacts with mercury(I) chloride to make mercury. ==Preparation== It is made by reacting [[phosphorus(III) oxide]] with water. It is also prepared by reaction of [[phosphorus trichloride]] with water, which produces [[hydrochloric acid]] too. ==Uses== It is used as a reducing agent. It is also used to kill certain [[bacteria]] that grow on [[plant]]s. ==Related pages== *[[Hypophosphorous acid]] *[[Phosphorus]] {{chem-stub}} [[Category:Phosphorus compounds]]