Answer:
The O is being oxidized, but at the same time, is being reducted.
Explanation:
H₂O₂(l) + ClO₂(aq) → ClO₂(aq) + O₂(g)
In this reaction, we have 4 compounds:
Hydrogen peroxide
Chlorine dioxide (twice)
Oxygen
In both dioxide, the Cl acts with +4 in oxidation state; the oxygen acts with -2.
Oxgen in ground state has 0, as oxidation number.
In peroxide, the H acts with +1 but the oxygen acts with -1.
Peroxide is making the oxidation number from the O in the ClO₂, to decrease (reduction) and to increase in the O, at the ground state.
Hydrogen peroxide is a good reducing and oxidizing agent at the same time.
