When is it inappropriate to use ionic equations to describe a reaction?

Question

This is for a study guide, and not for a test. I just can't find it in my text book. Please provide to some degree a little detail as to why.
Thanks.

Answer 1

Net ionic equations are preferred over molecular equations when the reaction is occurring in a solution. Since many compounds break down into ions when diluted, certain "spectator ions" end up not really being a part of the reaction. For instance:

AgNO3 + NaCl --> NaNO3 + AgCl.

Silver nitrate is soluble as is sodium chloride. Sodium nitrate is soluble but silver chloride is not. These ions, in a solution, would appear as such:

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

Since the nitrate and sodium ions end up being "spectators" the net ionic equation would appear as such:

Ag+ + Cl- --> AgCl

Whenever the reactants are solid or in any other case in which the reactants are not in a solution, net ionic equations are inappropriate because the compounds would not break down into ions.

Answer 2

its only appropriate to use ionic equations when the things that are reacting are ions. this means any solid-state reaction, any gas-state reaction, or any liquid-state reaction does not use ionic equations. However, reactions done in solution (and there are a lot of them in school classes) definitely need ionic equations.