1. Complete and Net Ionic Equations
The highest level of detail this unit.

2. What is a Complete Ionic Equation?
Complete Ionic equations show exactly what is happening in a reaction (especially a double replacement reaction).
Complete Ionic equations show all ions split apart for aqueous substances.
Any solids, liquids or gases stay together – so they are not written as ions.

3. What is a Net Ionic Equation?
A Net Ionic Equation shows only those parts of a reaction that are changing.
For example, if a reaction starts with an aqueous ion and in the end it is part of a solid, that ion has changed, and is included in the Net Ionic Equation.
Those ions that DO NOT change are called spectator ions.

4. For Example (this is in your notes)
Consider this molecular (normal) equation:
3KOH (aq) + Al(NO3)3 (aq)  3KNO3 (aq) + Al(OH)3 (s)
Everything that is aqueous (aq) is split apart in water.
The Complete Ionic Equation is:
3K+(aq) + 3OH-(aq) + Al3+(aq) + 3NO3-(aq)  3K+(aq) + 3NO3-(aq) + Al(OH)3(s)
Notice that all of the ions have charges, but solids don’t.

5. Getting from the Complete to the Net
Remember, Net Ionic equations only show those parts of the reaction that change.
Let’s look at the last example:
3K+(aq) + 3OH-(aq) + Al3+(aq) + 3NO3-(aq)  3K+(aq) + 3NO3-(aq) + Al(OH)3(s)
Please circle everything that is the exact same on both sides of the equation.

6. Getting from the Complete to the Net
The Net Ionic equation is shorter, because it does not include those spectator ions that you circled (the ones that stay the same).
3K+(aq) + 3OH-(aq) + Al3+(aq) + 3NO3-(aq)  3K+(aq) + 3NO3-(aq) + Al(OH)3(s)
So the Net Ionic Equation is:
3OH-(aq) + Al3+(aq)  Al(OH)3(s)

7. Try the next one (this is in your notes)
Consider this molecular (normal) equation:
Cu (s) + 2AgNO3 (aq)  2Ag (s) + Cu(NO3)2 (aq)
Everything that is aqueous (aq) is split apart in water.
The Complete Ionic Equation is:
Cu (s) + 2Ag+(aq) + 2NO3-(aq)  2Ag (s) + Cu2+ (aq) + 2NO3-(aq)
Notice that all of the ions have charges, but solids don’t.

8. Now, circle the spectator ions and write the Net Ionic Equation
The Complete Ionic Equation is:
Cu (s) + 2Ag+(aq) + 2NO3-(aq)  2Ag (s) + Cu2+ (aq) + 2NO3-(aq)
Circle those things that stay the same on both sides.
Now write the Net Ionic Equation:
Cu (s) + 2Ag+(aq)  2Ag (s) + Cu2+ (aq)

9. Again: (this is in your notes)
Consider this molecular (normal) equation:
CaCO3 (aq) + 2HCl (aq)  CaCl2 (aq) + H2O (aq) + CO2 (g)
Everything that is aqueous (aq) is split apart in water.
The Complete Ionic Equation is:
Ca2+(aq) + CO32-(aq) + 2H+(aq) + 2Cl-(aq)  Ca2+(aq) + 2Cl-(aq) + H2O(l) + CO2(g)
Notice that all of the ions have charges, but liquids and gases don’t.
Also, notice that when CaCl2 splits apart in water you get one Ca2+ ion and 2 Cl- ions…NOT Cl2 (which is a green poisonous gas…)

10. Now, circle the spectator ions and write the Net Ionic Equation
The Complete Ionic Equation is:
Ca2+(aq) + CO32-(aq) + 2H+(aq) + 2Cl-(aq)  Ca2+(aq) + 2Cl-(aq) + H2O(l) + CO2(g)
Circle those things that stay the same on both sides.
Now write the Net Ionic Equation:
CO32-(aq) + 2H+(aq)  H2O(l) + CO2(g)

11. Last One: (this is in your notes)
Consider this molecular (normal) equation:
H3PO4 (aq) + 3KOH (aq)  K3PO4 (aq) + 3H2O (l)
Everything that is aqueous (aq) is split apart in water.
The Complete Ionic Equation is:
3H+(aq) + PO43-(aq) + 3K+(aq) + 3OH-(aq)  3K+(aq) + PO43-(aq) + 3H2O(l)
Notice that all of the ions have charges, but liquids don’t.
Also, notice that when K3PO4 splits apart in water you get 3 K+ ions and one PO43- ion (not a K3+ ion)

12. Now, circle the spectator ions and write the Net Ionic Equation
The Complete Ionic Equation is:
3H+(aq) + PO43-(aq) + 3K+(aq) + 3OH-(aq)  3K+(aq) + PO43-(aq) + 3H2O(l)
Circle those things that stay the same on both sides.
Now write the Net Ionic Equation:
3H+(aq) + 3OH-(aq)  3H2O(l)