Question

The following half-reaction method is used to balance oxidation-reduction equations.

(1) Determine which atoms change oxidation state from reactant to product in the reaction.
(2) Identify and write half reactions (oxidation and reduction).
(3) Return to the original chemical equation to balance it.
(a) Insert the coefficients from the half reactions first.
(b) Inspect the number of each atom on each side for all elements.

Which important step is missing from this procedure?
Check other reactions similar to this one.
Name the elements that are involved in the reaction.
Make sure the reduction half reaction is identified first.
Balance the half reactions based on the number of electrons.

Answer 1

Balance the half-reactions based on the number of electrons.

Explanation: after writing each half‑reaction you must add electrons to balance charge (and if needed H2O/H+ or OH− to balance O and H), then multiply whole half‑reactions so the electrons lost = electrons gained before adding them together.