Question

Are spectator ions used to balance the half-reactions of a redox reaction? At what stage might spectator ions enter the balancing process?

Short answer

When a reaction is broken down into half-reactions, spectator ions are removed and then added back when the half-reactions are added after individual balancing.

Step-by-step solution

what is half-reaction

A redox reaction's half reaction is either the oxidation or reduction reaction component. The change in oxidation states of specific chemicals participating in the redox reaction is used to calculate a half-reaction.

Determining at which stage spectator ions might enter the balancing process

When a redox reaction is broken down into two half-reactions, any spectator ions are eliminated from the equations.

When the two half-reactions are joined together, any spectator ions that were eliminated from the equation are also included.