1. Solubility Rules and Precipitation Reactions
Chapter 7: Reactions in Aqueous Solutions!

2. Not all ionic compounds dissolve
Not all ionic compounds dissolve! Instead of doing experiments all the time to see which ones will dissolve, we use The solubility rules.

3. Solubility Rules All nitrates (NO3-) are soluble.
All ammonium (NH4+) or alkali (Li+, Na+, K+, Rb+, Cs+, Fr+) compounds are soluble.
All carbonates (CO32-), phosphates (PO4 3 -) and hydroxides (OH-) are insoluble except with the cations in Rule #2.
4. All chlorides (Cl-), bromides (Br-), and iodides (I-), are soluble except with Ag+, Pb2+, or Hg+.
5. All sulphates (SO42-) are soluble except with Ca2+, Sr2+, Ba2+, Ra2+, Pb2+,

4. Solubility Rules Con’t
6. All acetates (CH3COO) are soluble except Fe3+
7. Except for rule 1 and 2, carbonates, oxalates, sulfites, chromates, oxides, silicates, and phosphates are insoluble.
8. Except for rule 1 and 2, Sulfides are insoluble except for calcium, barium, strontium, magnesium.

5. Which of the following are soluble in water? SrSO4 NaNO3 PbCl2
Not soluble
soluble
Not soluble

6. Precipitation Reactions
When a solid doesn’t dissolve it is called insoluble. A solid that forms when two solutions are mixed is called a precipitate. Remember!!! State of matter is shown as a subscript in parentheses after the element or compound Solid (s) Aqueous/dissolved (aq) Gas (g)

7. Predict the products of the following reaction: (if no solid precipitate is formed, there is no reaction)
Pb(NO3)2(aq) + KI (aq)  Pb(NO3)2(aq) + 2KI (aq)  PbI2(s) + 2KNO3 (aq)
We know it is a solid
precipitate because it is
insoluble according to
the solubility rules.

8. A picture of the reaction:
Because K+ and NO3- remain dissolved, they are called spectator ions and are not included in the net ionic equation. Net Ionic Equation Pb2+ (aq) + 2I-(aq)  PbI2(s)
NO3-
NO3-
Pb2+ K+ I- K+
NO3-
PbI2(s)

9. Net Ionic Equation
Write the balanced chemical and net ionic equation for: Na2CO3(aq) + CaCl2(aq)  Step 1: Write the balanced chemical equation Na2CO3(aq) + CaCl2(aq)  CaCO3(s) + 2NaCl (aq) Step 2: Remove the spectator ions (those that are soluble). Ca2+(aq) + CO32-(aq)  CaCO3(s)
Insoluble precipitate