For the reaction kclo2⟶kcl+o2 kclo2⟶kcl+o2 assign oxidation numbers to each element on each side of the equation. k in kclo2: k in kclo2: k in kcl: k in kcl: cl in kclo2: cl in kclo2: cl in kcl: cl in kcl: o in kclo2: o in kclo2: o in o2: o in o2: which element is oxidized? kk oo clcl which element is reduced? oo kk cl

K in KClO2 = +1

Cl in KClO2 = +3

O in KClO2 = -2

K in KCl = +1

Cl in KCl = -1

O in O2 = 0

Chlorine is going from +3 to -1 so it is being reduced

Oxygen is going from -2 to 0 so it is being oxidized

Explanation:

Potassium is a constant +1

Chlorine could be -1, +1, +3, +5, or +7

Oxygen can be either -2 or +2

Every reactant has to equal zero if there is not a given charge.

Each element can only have certain charges, for example in the previous answer K = +5. Potassium can only be the charge of +1