4 ClO₃^- → (Cl)^- + 3 ClO₄^-

This is an oxidation-reduction (redox) reaction:

Cl^V + 6 e^- → Cl^-I (reduction)

3 Cl^V - 6 e^- → 3 Cl^VII (oxidation)

ClO₃^- is both an oxidizing and a reducing agent (disproportionation (dismutation)).

Reactants:

Products:

4 ClO3- → (Cl)- + 3 ClO4-