Answer:
H
2
O
2
(aq)+ClO
4
−
(aq)⟶O
2
(g)+ClO
2
−
(aq)
All atoms except H and O are balanced.
The oxidation number of Cl changes from 7 to 3. The change in the oxidation number is 4.
The oxidation number of O changes from -1 to 0. The change in oxidation number per O atom is 1.
Total change in the oxidation number for 2 oxygen atoms is 2.
To balance the increase in oxidation number with decrease in the oxidation number, multiply H
2
O
2
and O
2
with coefficients 2.
2H
2
O
2
(aq)+ClO
4
−
(aq)⟶2O
2
(g)+ClO
2
−
(aq)
To balance O atoms, add 2 water molecules on RHS.
2H
2
O
2
(aq)+ClO
4
−
(aq)⟶2O
2
(g)+ClO
2
−
(aq)+2H
2
O(l)
The oxygen atoms are already balanced.
This is the balanced chemical equation
