Unit Lesson Plan – Aqueous Equilibria II: Ksp and Solubility Product
Teacher:
Grade:
<Teacher>
Time Frame:
11
School:
Subject:
11 days
<School>
AP Chemistry
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HS-PS1-6 Refine the design of a chemical system by specifying a
change in conditions that would produce increased amounts of
products at equilibrium.* [Clarification Statement: Emphasis is on the
application of Le Chatelier’s Principle and on refining designs of
chemical reaction systems, including descriptions of the connection
between changes made at the macroscopic level and what happens
at the molecular level. Examples of designs could include different
ways to increase product formation including adding reactants or
removing products.] [Assessment Boundary: Assessment is limited to
specifying the change in only one variable at a time. Assessment
does not include calculating equilibrium constants and
concentrations.]
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Essential knowledge 6.A.1: In many classes of reactions, it is
important to consider both the forward and reverse reaction.
Essential knowledge 6.A.2: The current state of a system undergoing
a reversible reaction can be characterized by the extent to which
reactants have been converted to products. The relative quantities of
reaction components are quantitatively described by the reaction
quotient, Q.
Essential knowledge 6.A.3: When a system is at equilibrium, all
macroscopic variables, such as concentrations, partial pressures, and
temperature, do not change over time. Equilibrium results from an
equality between the rates of the forward and reverse reactions, at
which point, Q=K.
Essential knowledge 6.A.4: The magnitude of the equilibrium
constant, K, can be used to determine whether the equilibrium lies
toward the reactant side or product side.
Essential knowledge 6.B.1: Systems at equilibrium respond to
disturbances by partially countering the effect of the disturbance (Le
Chatelier’s principle)
Essential knowledge 6.B.2: A disturbance to a system at equilibrium
causes Q to differ from K, thereby taking the system out of the
original equilibrium state. The system responds by bringing Q back
into agreement with K, thereby establishing a new equilibrium state.
Essential knowledge 6.C.3: The solubility of a substance can be
understood in terms of chemical equilibrium
Learning Objective 6.1 The student is able to, given a set of
experimental observations regarding physical, chemical, biological, or
environmental processes that are reversible, construct an explanation
that connects the observations to the reversibility of the underlying
chemical reactions or processes.
Learning Objective 6.2 The student can, given a manipulation of a
chemical reaction or set of reactions (e.g., reversal of reaction or
addition of two reactions), determine the effects of that manipulation
on Q or K.
NGSS DCI:
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AP Standards:
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Note that this exact Smart Notebook presentation has not been used in the classroom, although all of the
material has. The pacing below is approximate based on a 40-45 minute class period. Feel free to adjust as
necessary and please provide your feedback!
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Learning Objective 6.3 The student can connect kinetics to
equilibrium by using reasoning about equilibrium, such as Le
Chatelier’s principle, to infer the relative rates of the forward and
reverse reactions.
Learning Objective 6.4 The student can, given a set of initial
conditions (concentrations or partial pressures) and the equilibrium
constant, K, use the tendency of Q to approach K to predict and
justify the prediction as to whether the reaction will proceed toward
products or reactants as equilibrium is approached.
Learning Objective 6.5 The student can, given data (tabular,
graphical, etc.) from which the state of a system at equilibrium can be
obtained, calculate the equilibrium constant, K.
Learning Objective 6.6 The student can, given a set of initial
conditions (concentrations or partial pressures) and the equilibrium
constant, K, use stoichiometric relationships and the law of mass
action (Q equals K at equilibrium) to determine qualitatively and/or
quantitatively the conditions at equilibrium for a system involving a
single reversible reaction.
Learning Objective 6.7 The student is able, for a reversible reaction
that has a large or small K, to determine which chemical species will
have very large versus very small concentrations at equilibrium.
Learning Objective 6.8 The student is able to use Le Chatelier’s
principle to predict the direction of the shift resulting from various
possible stresses on a system at chemical equilibrium.
Learning Objective 6.9 The student is able to use Le Chatelier’s
principle to design a set of conditions that will optimize a desired
outcome, such as product yield.
Learning Objective 6.10 The student is able to connect Le Chatelier’s
principle to the comparison of Q to K by explaining the effects of the
stress on Q and K.
Learning Objective 6.21 The student can predict the solubility of a
salt, or rank the solubility of salts, given the Ksp relevant values
Learning Objective 6.22 The student can interpret data regarding
solubility of salts to determine, or rank, the Ksp relevant values.
Learning Objective 6.23 The student can interpret data regarding the
relative solubility of salts in terms of factors (common ions, pH) that
influence the solubility.
Essential Questions
(What questions will the student be able to answer as a result of the instruction?)
How can the solubility rules be used to give a qualitative prediction as to whether a precipitate will form?
What is the difference between solubility and the solubility-product constant for a substance?
How do we use solubility product, Ksp, to make quantitative predictions about solubility?
What factors affect the solubility of a slightly soluble salt?
How can Ksp be used to selectively precipitate ions?
Knowledge & Skills
(What skills are needed to achieve the desired results?)
By the end of this unit, students will know:
How to explain the meaning of saturated solution
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and the relation of solubility to Ksp.
 How to solve for the other two quantities given
the Ksp, molar solubility or mass solubility for a
substance.
 How to use Le Chatelier’s principle to reason
qualitatively about the position of an equilibrium
after a disturbance to the equilibrium has
occurred.
 How the common ion effect and pH sensitivity
effect solubility.
 Predict whether a precipitate will form when
solutions are mixed by comparing Q and Ksp
values.
 Calculate the ion concentrations required to begin
precipitation and predict which ions will
precipitate first.
By the end of this unit, students will be able to:
 Rank the solubility of various salts using Ksp for
salts with identical numbers of ions.
 Interconvert between Ksp, molar solubility and
mass solubility for a substance.
 Determine the impact on the solubility of slightly
soluble salt after the addition of a common ion.
 Determine the impact of changes in pH to a
solution of a slightly soluble salt that has a basic
or acidic ion.
 Predict whether or not a precipitate will form
given the Ksp of a slightly soluble salt and the
concentration of its constituent ions.
 Determine which ion will precipitate first given the
Ksp of different slightly soluble salts and the
concentration of constituent ions.
 Determine the concentration of the first ion to
precipitate when the second ion begins to
precipitate in a solution containing different ions.
Assessment
(What is acceptable evidence to show desired results (rubrics, exam, etc.)? Attach Copy
During the Smart Notebook lesson designed to introduce concepts, students will be continually questioned on these
concepts using a combination of class work/homework questions and the SMART Response system. Classwork and
Homework questions will be discussed as a class and misconceptions will be addressed by the teacher prior to the
formal evaluations listed below.
Molar Solubility & Ksp Quiz
Factors that Affect Solubility Quiz
Selective Precipitation Quiz
Ksp and Solubility Product Test
Other assessments on the NJCTL website are optional and can be used as needed.
(What is the sequence of activities, learning experiences, etc, that will lead to desired results (the plan)?
Day
1
www.njctl.org
Topic
Classwork
Homework**
Introduction to Aqueous
Equilibria: Ksp & Solubility
Products
1-3
4-6
AP Chemistry
Ksp and Solubility Product
Note that this exact Smart Notebook presentation has not been used in the classroom, although all of the
material has. The pacing below is approximate based on a 40-45 minute class period. Feel free to adjust as
necessary and please provide your feedback!
2
Calculating Solubility from
Ksp
7-10
11-14
3
Calculating Solubility from
Ksp
15-18
19-22
4
Factors Affecting Solubility:
Common Ion Effect
23-26
27-30
5
Factors Affecting Solubility:
Changes in pH
31-34
35-38
7
Precipitation Reactions
39-41
42-44
8
Selective Precipitation
45-48
49-52
9
Conceptual Questions
Review
1-10
11-20
10
Free Response Review
1-4
5-8
11
Ksp and Solubility Product
Test
Test
N/A
* It may not be possible to complete labs in the order stated due to lab schedules. Other labs on the
NJCTL website are option and can be used as needed.
**HW Problems are currently not scaffolded from least to most difficult, but are instead listed in order of
topic. Teacher should pay special attention at the end of each class period when assigning HW so that
only problems related to the topic that was taught are being assigned.