Answer Key
Precipitation Lab
Purpose:
1. Identify the ions present in various aqueous solutions.
2. Combine solutions and identify the reactions that form
precipitates.
3. Write balanced molecular equation, complete ionic equation,
and a net ionic equation for each precipitation reaction.
Materials:

Small test tubes

Various solutions
Procedure:
1. Add 10-15 drops of the each reactant to a test tube.
2. Observe the results when the two solutions are combined in the test tube.
3. Record your observations for when the two solutions are mixed together and draw
and label the contents of the test tube.
4. If no precipitate (ppt) is detected, write NR or no reaction.
5. Clean your test tubes when finished
1
Reaction #1:
barium chloride + sodium sulfate 
Observations:
Balanced molecular equation:
BaCl2(aq) + Na2SO4(aq)  BaSO4(s) + 2NaCl(aq)
Complete ionic equation:
Ba2+ + 2Cl- + 2Na+ + SO42-  BaSO4(s) + 2Na+ + 2ClNet ionic equation:
Ba2+ + SO42-  BaSO4(s)
Name of product that makes the reaction occur:
Barium sulfate
Reaction #2:
sodium carbonate + silver nitrate 
Observations:
Balanced molecular equation:
Na2CO3(aq) + 2AgNO3(aq)  2NaNO3(aq) + Ag2CO3(s)
Complete ionic equation:
2Na+ + CO32- + 2Ag+ + 2NO3-  2Na+ + 2NO3- + Ag2CO3(s)
Net ionic equation:
CO32- + 2Ag+  Ag2CO3(s)
Name of product that makes the reaction occur: silver carbonate
2
Reaction #3:
Barium chloride + lead (II) nitrate 
Observations:
Balanced molecular equation:
BaCl2(aq) + Pb(NO3)2(aq)  Ba(NO3)2(aq) + PbCl2(s)
Complete ionic equation:
Ba2+ + 2Cl- + Pb2+ + 2NO3-  Ba2+ + 2NO3- + PbCl2(s)
Net ionic equation:
2Cl- + Pb2+  PbCl2(s)
Name of product that makes the reaction occur: lead (II) chloride
Reaction #4:
cadmium chloride + sodium sulfide 
Observations:
Balanced molecular equation:
CdCl2(aq) + Na2S(aq)  CdS(s) + 2NaCl(aq)
Complete ionic equation:
Cd2+ + 2Cl- + 2Na+ + S2-  CdS(s) + 2Na+ + 2ClNet ionic equation:
Cd2+ + S2-  CdS(s)
Name of product that makes the reaction occur: cadmium sulfide
3
Reaction #5:
barium chloride + silver nitrate 
Observations:
Balanced molecular equation:
BaCl2(aq) + 2AgNO3(aq)  Ba(NO3)2(aq)
+ 2AgCl(s)
Complete ionic equation:
Ba2+ + 2Cl- + 2Ag+ + 2NO3-  Ba2+ + 2NO3- + 2AgCl(s)
Net ionic equation:
Cl- + Ag+  AgCl(s)
Name of product that makes the reaction occur: silver chloride
Reaction #6:
copper (II) chloride + sodium carbonate 
Observations:
Balanced molecular equation:
CuCl2(aq) + Na2CO3(aq)  CuCO3(s) + 2NaCl(aq)
Complete ionic equation:
Cu2+ + 2Cl- + 2Na+ + CO32-  CuCO3(s) + 2Na+ + 2ClNet ionic equation:
Cu2+ + CO32-  CuCO3(s)
Name of product that makes the reaction occur: copper (II) carbonate
4
Reaction #7:
Iron (III) chloride + sodium hydroxide 
Observations:
Balanced molecular equation:
FeCl3(aq) + 3NaOH(aq)  Fe(OH)3(s) + 3NaCl(aq)
Complete ionic equation:
Fe3+ + 3Cl- + 3Na+ + 3OH-  Fe(OH)3(s) + 3Na+ + 3ClNet ionic equation:
Fe3+ + 3OH-  Fe(OH)3(s)
Name of product that makes the reaction occur: iron (III) hydroxide
Reaction #8:
Ammonium chloride + sodium hydroxide 
Observations:
Balanced molecular equation:
NH4Cl(aq) + NaOH(aq)  NH4OH(aq) + NaCl(aq)
Complete ionic equation:
N.R.
Net ionic equation:
N.R.
Name of product that makes the reaction occur: N.R.
5
Reaction #9:
barium chloride + sulfuric acid 
Observations:
Balanced molecular equation:
BaCl2(aq) + H2SO4(aq)  BaSO4(s) + 2HCl(aq)
Complete ionic equation:
Ba2+ + 2Cl- + 2H+ + SO42-  BaSO4(s) + 2H+ + 2ClNet ionic equation:
Ba2+ + SO42-  BaSO4(s)
Name of product that makes the reaction occur: barium sulfate
Reaction #10:
barium nitrate + sodium sulfate 
Observations:
Balanced molecular equation:
Ba(NO3)2(aq) + Na2SO4(aq)  BaSO4(s) + 2NaNO3(aq)
Complete ionic equation:
Ba2+ + 2NO3- + 2Na+
+ SO42-  BaSO4(s) + 2Na+ + 2NO3-
Net ionic equation:
Ba2+ + SO42-  BaSO4(s)
Name of product that makes the reaction occur: barium sulfate
6
Reaction #11:
barium chloride + sodium hydroxide 
Observations:
Balanced molecular equation:
BaCl2(aq) + 2NaOH(aq)  Ba(OH)2(s) + 2NaCl(aq)
Complete ionic equation:
Ba2+ + 2Cl- + 2Na+
+ 2OH-  Ba(OH)2(s) + 2Na+ + 2Cl-
Net ionic equation:
Ba2+ + 2OH-  Ba(OH)2(s)
Name of product that makes the reaction occur: barium hydroxide
Reaction #12:
lead (II) nitrate + potassium iodide 
Observations:
Balanced molecular equation:
Pb(NO3)2(aq) + 2KI(aq)  PbI2(s) + 2KNO3(aq)
Complete ionic equation:
Pb2+ + 2NO3- + 2K+ + 2I-  PbI2(s) + 2K+ + 2NO3Net ionic equation:
Pb2+ + 2I-  PbI2(s)
Name of product that makes the reaction occur: lead (II) iodide
7