What are spectator ions?
Spectator ions are ions that remain unchanged during a chemical reaction. They are found in reactions between aqueous solutions (aq). For example, consider the reaction between sodium chloride solution and silver nitrate solution. The products are sodium nitrate solution and a precipitate of insoluble silver chloride. The ionic equation for this reaction is: Na+(aq) + Cl-(aq) + Ag+(aq) + NO3-(aq) –> AgCl(s) + Na+(aq) + NO3-(aq) The sodium ions and the nitrate ions have not changed during the reaction, and so they are called ‘spectator ions’. The silver ions and the chloride ions have joined together to form a solid, so they are not spectator ions.
