Final answer:
Net ionic equations focus on the ions that undergo a chemical change during a reaction, such as the formation of a precipitate. In the example provided, the net ionic equation for the reaction between CaCl2 and Pb(NO3)2 reduces to the formation of solid PbCl2, as the chloride and nitrate ions are spectators.
Step-by-step explanation:
To write the net ionic equations for the reactions given, the key is to identify the ions that participate in the reaction and generate products. For example, when CaCl2(aq) reacts with Pb(NO3)2(aq), the relevant species that form a precipitate are the Ca2+ ions and the NO3− ions. In this resulting net ionic equation:
- Ca2+ (aq) + Pb2+ (aq) + 2 Cl− (aq) + 2 NO3− (aq) → Ca(NO3)2(aq) + PbCl2(s)
- Ca2+ (aq) + Pb2+ (aq) → PbCl2(s)
Here, the chloride and nitrate ions are spectator ions and do not change during the course of the reaction. Thus, they are omitted from the net ionic equation, which simply shows the formation of the solid precipitate PbCl2.