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PSI AP Chemistry
Chapter Problems Part C: Precipitation Reactions
Name _______________________
Classwork:
1. Write proper net-ionic equations (sans spectator ions, including proper
charges and phases for reacting ions) for the following:
a. Aqueous lead(II) nitrate is mixed with aqueous sodium carbonate
b. Aqueous barium chloride is mixed with aqueous silver acetate
c. Aqueous copper(I) nitrate is mixed with aqueous sodium phosphate
d. Solid potassium bromide is added to an aqueous HCl solution
2. A student is given a beaker containing an aqueous solution of sodium sulfate
and one or possibly all of the following ions (Ag+, CO32-, NO3-)
a. Which ion must not be present and provide a justification for your
answer?
b. Adding which of the two (aqueous barium nitrate or aqueous
copper(II) nitrate) would determine if the carbonate ion is present?
Explain why the solution proposed would confirm the presence of the
carbonate ion and how adding the other solution would not.
3. A student is provided three beakers with 100 mL of the contents as shown
below:
A
B
C
0.1 M CaBr2
a)
b)
c)
d)
0.1 M AgNO3
0.1 M K2CO3
What would be the expected reaction if beakers A and C were mixed?
What would be the expected reaction if beakers A and B were mixed?
What would be the expected reaction if beakers B and C were mixed?
If beakers A and B were mixed:
i. What would be the expected mass of precipitate formed?
ii. What would be the concentration of the following ions in solution
after the reaction was complete?
Ca2+
BrAg+
NO3-
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AP Chemistry
Mole Concept, Reactions, Stoichiometry
Answers
1. Write proper net-ionic equations (sans spectator ions, including proper
charges and phases for reacting ions) for the following:
a. Aqueous lead(II) nitrate is mixed with aqueous sodium carbonate
Pb2+(aq) + CO32-(aq)  PbCO3(s)
b. Aqueous barium chloride is mixed with aqueous silver acetate
Cl-(aq) + Ag+(aq)  AgCl(s)
c. Aqueous copper(I) nitrate is mixed with aqueous sodium phosphate
3Cu+(aq) + PO43-(aq)  Cu3PO4(s)
d. Solid potassium bromide is added to an aqueous HCl solution
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2. A student is given a beaker containing an aqueous solution of sodium sulfate
and one or possibly all of the following ions (Ag+, CO32-, NO3-)
a. Which ion must not be present and provide a justification for your
answer?
Ag+ as it would form a precipitate with the sulfate ion already in
solution
b. Adding which of the two (aqueous barium nitrate or aqueous
copper(II) nitrate) would determine if the carbonate ion is present?
Explain why the solution proposed would confirm the presence of the
carbonate ion and how adding the other solution would not.
Copper(II) nitrate is the solution to add as the Cu2+ ion would only
form a precipitate with the carbonate ion, not the sulfate so an
observed precipitate would confirm the carbonate ion. The barium
nitrate solution would form a precipitate with the sulfate already
in solution and with any carbonate ion that might be there as well
so the formation of a precipitate would not necessarily indicate the
carbonate ion.
3. A student is provided three beakers with 100 mL of the contents as shown
below:
A
B
C
0.1 M CaBr2
0.1 M AgNO3
0.1 M K2CO3
a) What would be the expected reaction if beakers A and C were mixed?
Ca2+(aq) + CO32-(aq)  CaCO3(s)
b) What would be the expected reaction if beakers A and B were mixed?
Ag+(aq) + Br-(aq)  AgBr(s)
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AP Chemistry
Mole Concept, Reactions, Stoichiometry
c) What would be the expected reaction if beakers B and C were mixed?
2Ag+(aq) + CO32-(aq)  Ag2CO3(s)
d) If beakers A and B were mixed:
j. What would be the expected mass of precipitate formed?
1.88 grams
ii. What would be the concentration of the following ions in solution
after the reaction was complete?
Ca2+
BrAg+
NO3Ca2+(aq)
0.01 moles/0.2 L = 0.05 M
Br-(aq)
0.02 moles – 0.01 moles = 0.01 moles/0.2 L = 0.05 M
Ag+(aq)
Approximately 0 M
NO3-(aq)
0.01 moles/0.2 L = 0.05 M
www.njctl.org
AP Chemistry
Mole Concept, Reactions, Stoichiometry