disproportion reaction are those reaction where both oxidation and reduction takes place simultaneously.
ex 3H3PO3-----3H3PO4 + PH3
Oxidation state of phosphorus in phosphorus acid is +3 in ph3 it is -3 , in orthophosphoric it is +5
+3------+5(oxidation)
+3----- -3(reduction)
thanks and regards
sunil kr
askIItian faculty