Net Ionic Equations

Chemical reactions can be written so that only the substances undergoing a net chemical change are included in the equation.

For example, the reaction:

NaCl + AgNO₃ --> AgCl + NaNO₃

can be rewritten as follows since three of the four compounds are soluble ionic compounds:

Ag⁺ + NO₃^- + Na⁺ + Cl^- --> AgCl + Na⁺ + NO₃^-

Since the Na⁺ and NO₃- do not undergo chemical change they can be subtracted from both sides leaving:

Ag⁺ + Cl^- --> AgCl

The Na⁺, K⁺ and NO₃^- are referred to as spectator ions. That is they are not part of the reaction because they do not undergo any net chemical change during the reaction. These three ions are commonly (although not always!) spectator ions.

Click here to see how we dicovered net ionic reactions in this experiment.