UPSEE 2019 Solved Paper

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.