1. Net Ionic Equations

2. Net Ionic Equations…
…describe a chemical reaction in solution recognizing the role of dissociation.

3. 3 steps Non Ionic equation (aka balanced chemical equation)
Total ionic equation
Net ionic equation

4. Example
Solutions of lead (II) nitrate and potassium iodide are mixed.

5. Non ionic equation Pb(NO3)2 + KI ---> (aq) 2 (aq) PbI2 + KNO3 (s) 2

6. Total ionic equation Dissociate or ionize everything that is:
Aqueous and ionic
Aqueous and acid

7. Total ionic Pb(NO3)2 + KI ---> PbI2 + KNO3 2 (aq) (s) Dissociate
Pb2+(aq) + 2NO3¯(aq) +
2K+(aq) + 2I¯(aq) --->
PbI2(s) +
2K+(aq) + 2NO3¯(aq)
NOT aqueous so not dissociated

8. Spectator species (entities)
A spectator species is a species (entity) that does not change in the reaction, is not involved in the reaction.

9. Cancel spectator species
Total ionic equation:
Pb2+(aq) + 2NO3¯(aq) +
2K+(aq) + 2I¯(aq) --->
PbI2(s) +
2K+(aq) + 2NO3¯(aq)
What remains is the net ionic equation.

10. Net ionic equation
Pb2+(aq) + 2I¯(aq) ---> PbI2(s)

11. Example Chlorine gas is bubbled through a solution of sodium fluoride.
Non ionic equation:
Cl2(g) + 2NaF(aq) ---> F2(g) + 2NaCl(aq)

12. Total ionic equation Dissociate everything that is:
Aqueous and ionic or aqueous and acid
Cl2(g) + 2NaF(aq) ---> F2(g) + 2NaCl(aq)
Cl2(g) +
2Na+(aq) + 2F¯(aq) --->
F2(g) +
2Na+(aq) + 2Cl¯(aq)

13. Net Ionic Equation Cancel all spectator species: Cl2(g) +
2Na+(aq) + 2F¯(aq) --->
F2(g) +
2Na+(aq) + 2Cl¯(aq)
What remains is the net ionic equation:
Cl2(g) + 2F¯(aq) ---> F2(g) + 2Cl¯(aq)

14. Watch for:
Occasionally there are no spectator species. Then the total and the net are the same.
Occasionally all species in the total ionic equation are spectators, everything cancels. What does this mean??