Given reaction, P4+3NaOH+3H2O→3NaH2PO2+PH3 Oxidation state of P in P4=0 Oxidation state of P in PH3=−3 Oxidation state of P inNaH2PO2=+1 So, P40→
−3
PH
3+H2
+1
PO
2− Hence, this reaction is an example of disproportionation reaction. It is a chemical reaction, typically a redox reaction, where a molecule is transformed into two or more dissimilar products.