AP Chemistry Stoichiometry Review Part II focuses on key concepts in stoichiometry, including precipitation reactions, acid-base reactions, and mole calculations. This resource is designed for high school students preparing for AP Chemistry exams, providing practice problems and detailed solutions. Topics covered include writing complete chemical equations, calculating moles of precipitates, and determining volumes of reactants needed for reactions. The review also emphasizes understanding limiting reactants and the solubility of various compounds. Ideal for students looking to reinforce their knowledge and problem-solving skills in chemistry.

Key Points

  • Covers precipitation reactions and acid-base reactions in stoichiometry.
  • Includes practice problems for calculating moles and precipitates.
  • Explains the concept of limiting reactants in chemical reactions.
  • Provides detailed solutions for various stoichiometric calculations.
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AP CHEMISTRY
TOPIC 2: STOICHIOMETRY, REVIEW PART II Day 21:
Stoichiometry:
Precipitation Reactions
Acids and Bases
1) Write the COMPLETE EQUATION, if there is no reaction, write N.R.
a) A hydrochloric acid solution (an acid) reacts with aqueous lead(II) chlorate solution (NOT a base).
_2_ HCl
(aq)
+ ___ Pb(ClO
3
)
2
(aq)
_2_ HClO
3
(aq)
+ PbCl
2
(s)
b) An aqueous potassium sulfide solution reacts with aqueous bismuth(III) acetate solution.
_3_ K
2
S
(aq)
+ _2_ Bi(C
2
H
3
O
2
)
3
(aq)
_6_ KC
2
H
3
O
2
(aq)
+ ___ Bi
2
S
3
(s)
c) An aqueous potassium hydroxide solution reacts with aqueous nitric acid solution.
___ KOH
(aq)
+ ___ HNO
3
(aq)
___ HOH
(l)
+ ___ KNO
3
(aq)
d) An aqueous calcium hydroxide solution reacts with aqueous copper(II) chloride solution.
___ Ca(OH)
2 (aq)
+ ___ CuCl
2
(aq)
___ CaCl
2
(aq)
+ ___ Cu(OH)
2
(s)
2) Calculate the number of moles of the precipitate formed when 200.5 grams of barium nitrate (which is dissolved in enough
water so that the final volume of the solution is 2.5 liters) is mixed with a sodium phosphate solution (which is in excess).
SHOW ALL WORK
_3_ Ba(NO
3
)
2 (aq)
+ _2_ Na
3
PO
4
(aq)
_6_ NaNO
3
(l)
+ ___ Ba
3
(
PO
4
)
2
(s)
3 2 3 2 3 4
34
32
200.5 ( ) 1 ( ) 1
0.26
261.344 3 ( )
g Ba NO mol Ba NO mol Ba PO
mol Ba PO
g mol Ba NO
___ PbCl
2
(s)
___ Bi
2
S
3
(s)
___ Cu(OH)
2
(s)
___ Ba
3
(
PO
4
)
2
(s)
3) Calculate the mass of the precipitate that is formed when 620 mL of a 2.35 M calcium chloride solution is added to 375 mL of a
3.33 M copper(II) sulfate solution. SHOW ALL WORK
___ CaCl
2
(aq)
+ ___ CuSO
4
(aq)
___ CuCl
2
(aq)
+ ___ CaSO
4
(s)
42
2
42
375 1 3.33 1 1000
531
1000 1 2.35 1
mL L mol CuSO mol CaCl mL
L
mL CaCl
mL L mol CuSO mol CaCl L
CuSO
4
is the Limiting Reactant
44
4
44
375 1 3.33 1 136.14
170
1000 1 1
mL L mol CuSO mol CaSO g
g CaSO
mL L mol CuSO mol CaSO
4) What volume of a 4.50 M silver nitrate solution will react completely with 84.0 mL of a 4.53 M hydrochloric solution?
___ AgNO
3
(aq)
+ ___ HCl
(aq)
___ HNO
3
(aq)
+ ___ AgCl
(s)
84.0 1 4.53 1
0.0846
1000 1 4.5
mL HCl L mol HCl mol AgCl
L
L AgCl
mL L mol HCl mol AgCl
OR 84.6 mL
5) Calculate the volume (in milliliters), of the water formed when 300. mL of a 2.58 M sulfuric acid solution is mixed with 400.
mL of a 2.30 M sodium hydroxide solution. SHOW ALL WORK
___ H
2
SO
4
(aq)
+ _2_ NaOH
(aq)
_2_ HOH
(l)
+ ___ Na
2
SO
4
(aq)
24
24
24
400. 1 2.30 1 1000
178
1000 2 2.58 1
mL L mol NaOH mol H SO mL
L
mL H SO
mL L mol NaOH mol H SO L
NaOH is the Limiting Reactant
___ CaSO
4
(s)
___ AgCl
(s)
6) A student dissolves 525 grams of potassium oxide in enough distilled water so that the final volume is 3.55 liters in a
volumetric flask labeled “A”. Then in a different flask, she dissolves 623.25 grams of aluminum nitrate in enough
distilled water so that the final volume is 5.66 liters in a volumetric flask labeled “B”. She then mixes the two solutions
together. What is the mass, in grams, of the precipitate formed? SHOW ALL WORK
_3_ K
2
O
(aq)
+ _2_ Al(NO
3
)
3
(aq)
_6_ KNO
3
(l)
+ ___ Al
2
O
3
(s)
Al(NO
3
)
3
is the Limiting Reactant
_
33
3 3 2 3
23
3 3 2 3
623.25 ( )
1 ( ) 1
101.96
149
213.001 2 ( ) 1
g Al NO
mol Al NO mol Al O
g
g Al O
g mol Al NO mol Al O
7) Below are the products from “MANY different reactions”, circle those that would be not soluble in solution.
CaSO
4
Pb(C
2
H
3
O
2
)
2
(NH
4
)
2
CrO
4
Sr(OH)
2
Zn
3
(PO
4
)
2
Na
2
O
(NH
4
)
2
O
CuSO
4
Ca(ClO
3
)
2
Cs
3
PO
4
BaS
Ti
2
(CO
3
)
3
AgNO
3
Ni(OH)
3
MgCrO
4
CoI
3
AuCl
3
MgCO
3
LiOH
Pb(ClO
3
)
2
Mg(OH)
2
Au(ClO
3
)
3
Cr(C
2
H
3
O
2
)
3
BaSO
4
Mn
2
O
3
CuCl
2
FeCl
3
HgO
K
2
CO
3
AgBr
RbOH
NH
4
NO
3
___ Al
2
O
3
(s)
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End of Document
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FAQs

What are precipitation reactions in stoichiometry?
Precipitation reactions occur when two aqueous solutions react to form an insoluble solid, known as a precipitate. In stoichiometry, these reactions are important for understanding how to predict the products of a reaction and calculate the amounts of reactants needed. For example, when mixing barium nitrate with sodium phosphate, barium phosphate precipitates out of the solution. Understanding these reactions helps students grasp the principles of solubility and the conservation of mass.

How do you calculate moles of a precipitate formed?
To calculate the moles of a precipitate formed in a reaction, you first need to write the balanced chemical equation. Then, determine the limiting reactant by calculating the moles of each reactant based on their initial concentrations and volumes. Once the limiting reactant is identified, use stoichiometric ratios from the balanced equation to find the moles of the precipitate produced. This process is crucial for accurate quantitative analysis in chemistry.

What is the significance of limiting reactants in stoichiometry?
Limiting reactants are crucial in stoichiometry as they determine the maximum amount of product that can be formed in a chemical reaction. Identifying the limiting reactant allows chemists to predict how much product will be produced and how much of the other reactants will remain unreacted. This concept is essential for efficient resource management in chemical processes and is a key focus in AP Chemistry courses.

What types of problems are included in the stoichiometry review?
The stoichiometry review includes a variety of problems such as writing complete chemical equations, calculating the number of moles of reactants and products, and determining the mass of precipitates formed in reactions. Additionally, it covers calculations involving volumes of solutions and concentrations, providing a comprehensive practice for students. These problems are designed to enhance problem-solving skills and prepare students for the AP Chemistry exam.

How do acid-base reactions relate to stoichiometry?
Acid-base reactions are a key aspect of stoichiometry, as they involve the neutralization of an acid by a base to form water and a salt. In stoichiometric calculations, understanding the molar relationships between the acid and base is essential for determining the amounts needed for complete reaction. These reactions are often represented in balanced equations, allowing students to practice calculating moles, volumes, and concentrations involved in the reaction.