H3PO3 is a white solid at room temperature, density 1.65 g/cm3, melting point 73.6 ̊C (164.48 ̊F). It is deliquescent, soluble in water and alcohol. H3PO3 example reactions: • H3PO3 + 3KOH = 3H2O + K3PO3 • P4O6 + 6H2O = 4H3PO3 H3PO3 decomposes at 200 ̊C: • 4H3PO3 = 3H3PO4 + PH3↑
