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Acid-base properties

Phosphorous acid has a pK_a in the range 1.26-1.3.
: pK_a = 1.3It is a diprotic acid, the hydrogenphosphite ion, is a weak acid:
: pK_a = 6.7

The conjugate base is called hydrogen phosphite, and the second conjugate base, , is the phosphite ion. (Note that the