Question

what will be the reaction when H3PO3 is heated

Answer 1

H3PO3,on heating, undergoes disproportionation reaction to form PH3 and H3PO4. The oxidation numbers of P in H3PO3,PH3, and H3PO4 are +3, - 3, and +5 respectively. As the oxidation number of the same element is decreasing and increasing during a particular reaction, the reaction is a disproportionation reaction.

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Answer 2

The reaction that ill take place when H3PO3 is heated is given below :-


                  4H3PO3                →→→             3H3PO4             +            PH3
      (Orthophosphorpous acid)             (Orthophosphoric acid)   

Here oxidation numbers of "P" in H3PO3, PH3, and H3PO4 are +3, −3, and +5.

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