1. 2NaBr(aq) + Pb(OH)2(aq)  PbBr2(s) + 2NaOH(aq)
Warmup
1. Write (predict products too) and balance this equation: sodium bromide and lead(II)hydroxide solutions are mixed to create a precipitate in a basic solution.
2NaBr(aq) + Pb(OH)2(aq)  PbBr2(s) + 2NaOH(aq)
You’ll need your solubility rules, ion sheets, and Oops I Did it Again Lab today.

2. Net Ionic Equations

3. Part I: Net Ion Equations
Actually….in double replacement reactions, we only show the species that changed phase, or that were integrated or disintegrated into something new. We eliminate “spectator ions” and just show the net ionic equation. Also, we have to use solubility rules to predict the precipitate.
2Na++ 2Br-+ Pb2+ + 2OH-  Pb2+ + 2Br- + 2Na+ + 2OH- 2Br-(aq) + Pb2+(aq)  PbBr2(s)

4. For each pair of ionic compounds shown: a
For each pair of ionic compounds shown: a. Split the reactants into ions and write the complete ionic equation. b. Write the net ionic equation. Indicate solid precipitates (insoluble compounds) in the products. Na2S(aq) + AlCl3(aq)  ??????????? Na+ + S2- + Al3+ + Cl-  Na+ + S2- + Al3+ + Cl- 3S2-(aq) + 2Al3+(aq)  Al2S3(s) Ba(NO3)2(aq) + Ag2SO4(aq)  ??????????? Ba2+ + NO3- +Ag+ + SO42-  Ba2+ + NO3- + Ag+ + SO42- Ba2+(aq) + SO42- (aq)  BaSO4(s)

5. Hint: chlorates tend to be soluble For each pair of ionic compounds shown: a. Split the reactants into ions and write the complete ionic equation. b. Write the net ionic equation. Indicate solid precipitates (insoluble compounds) in the products. Pb3(PO4)2(aq) + NaClO3(aq)  Pb2+ +PO43- + Na+ + ClO3-  Pb2++ PO43- +Na+ + ClO3- NO REACTION KI(aq) + Pb(NO3)2(aq)  K+ + I- + Pb2+ + NO3-  K+ + I- + Pb2+ + NO3- 2I-(aq) + Pb2+(aq)  PbI2(s)

6. K2CrO4(aq) + Ba(NO3)2 (aq)  product
A potassium chromate solution and barium nitrate solution are combined, producing a yellow precipitate. Write the net ionic equation for this reaction and identify the precipitate.
K2CrO4(aq) + Ba(NO3)2 (aq)  product
molecular equation
2K+ +CrO42- +Ba2+ + 2NO3- 2K+ +CrO42- +Ba2+ +2NO3-
complete ionic equation
 2KNO3(?) and BaCrO4(?)
CrO42-(aq) + Ba2+(aq)  BaCrO4(s)

7. (do these with a neighbor, 5 minutes)
Write the net ionic equation for the reaction, if any, that occurs when aqueous solutions of the following are mixed. You will have to predict and write the products!
Chromium(III) chloride and sodium hydroxide
Silver nitrate and ammonium carbonate
Copper(II)sulfate and mercury(I) nitrate
Strontium nitrate and potassium iodide

8. Chromium(III) chloride and sodium hydroxide
Cr3+(aq) + 3OH-(aq)  Cr(OH)3(s)
b. Silver nitrate and ammonium carbonate
Ag+(aq) + CO32-(aq)  Ag2CO3(s)
c. Copper(II)sulfate and mercury(I) nitrate
SO42-(aq) + Hg22+(aq)  Hg2SO4(s)
d. Strontium nitrate and potassium iodide
Sr2+ + NO3- + K+ + I-  Sr2+ + NO3- + K+ + I-
NO REACTION

9. Oooops I Did it Again! Lab!
Spend 10 minutes on prelab
Please label all 8 of your disposable pipets and do NOT throw them away!