The oxidation number of phosphorus in pyrophosphoric acid is
Pyrophosphoric acid H4P2O7 Let oxidation state of phosphorus is x(4 × 1 + (– 2) × 7 + 2 x) = 0 ∴ 2x= 10 or x= +5
The compound that can work both as an oxidizing and reducing agent is:
H2O2 can act both as an oxidizing and reducing agent,as oxygen has intermediate oxd. state in it.