Ncert Exercises & Solutions

7.15 Give the disproportionation reaction of H₃PO₃.

On heating, orthophosphorus acid (H₃PO₃) disproportionates to give orthophosphoric acid ( $H_{3} {PO}_{4}$ ) and phosphine (PH₃). The oxidation states of P in various species involved in the reaction are mentioned below.

$4 H_{3} P^{+ 3} O_{2} \to 3 H_{3} P^{+ 5} O_{4} + {PH}_{3}$