What happens when H3PO3 is heated?


H3PO3 on heating dissociates into orthophosphoric acid(H3PO4) and phosphine (PH3). Since, the oxidation states of orthophosphorous acid (H3PO3), orthophosphoric acid (H3PO4) and phosphine (PH3) are +3,+5 and -3 respectively, this reaction is known as a disproportionate reaction (since the oxidation states of one of the product are positive and the other is negative). The reaction is as follows.



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