APS Science 2011
APS Science Curriculum Unit Planner
Grade Level/Subject
Chemistry
Stage 1: Desired Results
Enduring Understanding
Topic 6 Solutions: Solutions concentrations can be understood by looking at molar relationships. Acids and
Bases are special types of solutions.
Correlations
Unifying Understanding
Behavior of solutions can be explained by interactions at the particle level.
VA SOL
CH.4 The student will investigate and understand that chemical quantities are
based on molar relationships. Key concepts include
c) solution concentrations; and
d) acid/base theory; strong electrolytes, weak electrolytes, and nonelectrolytes;
dissociation and ionization; pH and pOH; and the titration process
CH.5 The student will investigate and understand that the phases of matter are
explained by kinetic theory and forces of attraction between particles. Key
concepts include
g) colligative properties.
NSES (grade level)
AAAS Atlas
Essential Questions
 How do features of the atom at the particle level explain the behavior of the atom?
 How does the unique nature of solute-solvent interaction explains the solution process?
 What are the different ways that solution concentrations are expressed?
 How can concentrations of solutions affect chemical interactions?
 What are the characteristics that define an acid and a base?
 What are the properties of acids and bases?
 How is acidity measured?
 What are the uses of titrations?
 How are colligative properties quantified using solution concentration?
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APS Science 2011
Knowledge and Skills
Students should know:
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Mixtures maybe homogeneous or heterogeneous.
Solute is defined as the part of a solution being dissolved. The solvent is the part of the solution doing
the dissolving. Solutions may be composed of any combination of phases of matter. Solid/Solid
solutions are called alloys.
Molarity = moles/dm3 or moles of solute/L of solution.
[ ] refers to molar concentration.
When solutions are diluted, the moles of solute present initially remain.
The saturation of a solution is dependent on the amount of solute present in the solution. Solutions may
be unsaturated or saturated. Under unique situations, some solutions may be supersaturated.
The terms concentrated and dilute are qualitative terms
Ionic substances may dissociate into ions in solutions.
Solubility may be graphed as a function of temperature and pressure.
Solutions may be defined as electrolytes or non electrolytes.
The degree of solubility of a substance in a solvent is dependent on forces of attraction and the general
rule is “like dissolves like.”
Two important classes of compounds are acids and bases. Acids and bases are defined by several
theories. According to The Arrhenius theory of, acids are characterized by their sour taste, low pH, and
the fact that they turn litmus paper red. According to Tthe Arrhenius theory of , bases are characterized
by their bitter taste, slippery feel, high pH, and the fact that they turn litmus paper blue.
According to The Bronsted-Lowry theory of, acids are proton donors, whereas bases are proton
acceptors.
Acids and bases dissociate in varying degrees. Strong electrolytes dissociate completely. Weak
electrolytes dissociate partially. Non-electrolytes do not dissociate
pH is a number scale ranging from 0 to 14 that represents the acidity of a solution. The pH number
denotes hydrogen (hydronium) ion concentration. The pOH number denotes hydroxide ion
concentration. The higher the hydronium [H3O+] concentration, the lower the pH.
pH + pOH = 14
Strong acid-strong base titration is the process that measures [H++] and [OH--].
Indicators show color changes at certain pH levels.
A liquid’s boiling point and freezing point are affected by changes in atmospheric pressure. A liquid’s
boiling point and freezing point are affected by the presence of certain solutes.
Students should be able to:
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perform calculations involving the molarity of a solution, including dilutions.
interpret solubility curves.
differentiate between the defining characteristics of the Arrhenius theory of acids and bases and the
Bronsted-Lowry theory of acids and bases.
identify common examples of acids and bases, including vinegar and ammonia.
compare and contrast the differences between strong, weak, and non-electrolytes
relate the hydronium ion concentration to the pH scale.
perform titrations in a laboratory setting using indicators.
examine the polarity of various solutes and solvents in solution formation.
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APS Science 2011
Stage 2: Assessment Evidence
Prior Knowledge and Skills
 Basic Algebra
 Rules for Significant Figures
 Mole Calculations
 Stoichiometry
Formative Assessment
Summative Assessment
 Student participation
 Laboratory Reports
 Homework (readings, questions, and
 Tests and Quizzes
problems)
 Laboratory assessment understanding
models
Stage 3: Learning Plan
References to Adopted Materials
Prentice Hall Chemistry
Text
 Chapter 2 Matter and Change Section 2.2 Mixtures pp.44-47
 Chapter 15 Water and Aqueous Solutions
 Chapter 16 Solutions
 Chapter 19 Acids, Bases and Salts
Guided Reading and Study Workbook:
 Chapter 2 pp.13-14
 Chapter 15 pp159-167
 Chapter 16 pp.168-175
 Chapter 19 pp.209-218
Formatted: Font: 11 pt
Holt Chemistry
Text
 Chapter 1 - The Science of Chemistry ,Section 3- How is Matter Classified?
 Chapter 13 –Solutions
 Chapter 15 Acids and Bases
Study Guide
Chapter 1 p.1-7
Chapter 13 p.104-114
Chapter 15 p.123-132
Suggested Investigations
 Kool-aid Solubility Lab –Calculate the molarity of kool-aid solutions. Discuss spectroscopy by
comparing colors of concentrated vs. dilute solutions
 Conductivity Lab – Testing the Conductivity of Electrolyte and Non-Electrolyte Solutions
 Small Scale Titration Lab
 Titration of Vinegar Lab
 Colligative Properties – Making Ice Cream
Prentice Hall Activities
 Teacher Demo –Electrolytes and Non Electrolytes TE p.453
 p.453 Small Scale Lab: Electrolytes
 p.470 Inquiry Lab: Salt and the Freezing Point of Water
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APS Science 2011
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Teacher Demo – Solubility of Gases TE p.475
Teacher Demo – Reactive Acids TE p.588
LM p. 179 Lab 28 Water of Hydration
LM p.189 Lab 30 Factors Affecting Solution Formaton
LM p.247 Lab 40 Estimation of pH
LM p. 251 Lab 41 Reactions of Acid
LM p. 255 Lab 42 Neutralization Reactions
Holt Activities
 Activity TE p. 482 Edible Example of Freezing Point Depression
 Teacher Demo TE p.483 Insta-Freeze
 Teacher Demo TE p546 Effects of pH on Chlorophyll Stability
Outdoor Education Applications
 Water Quality Testing at the Outdoor Lab
Resources
Web Sites
 http://www.chem.purdue.edu/gchelp/ - Visualization and Problem Solving for General Chemistry –
Section on Solutions
Explorelearning.com
 pH Analysis Gizmo- Test the acidity of common substances using pH paper. Materials including
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soap, lemon juice, milk, and oven cleaner can be tested by comparing the color of pH strips to a
standard scale.
Colligative Propertie Gizmo - Determine how the physical properties of a solvent are dependent
on the number of solute particles present. Measure the vapor pressure, boiling point, freezing
point, and osmotic pressure of pure water and a variety of solutions. Compare the effects of four
solutes (sucrose, sodium chloride, calcium chloride, and potassium chloride) on these physical
properties.
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http://phet.colorado.edu/ - Fun, interactive, research-based simulations of physical phenomena from the
PhET project at the University of Colorado.
 Acid and Base Solutions-How do strong and weak acids differ? Use lab tools on your computer
to find out! Dip the paper or the probe into solution to measure the pH, or put in the electrodes
to measure the conductivity. Then see how concentration and strength affect pH. Can a weak
acid solution have the same pH as a strong acid solution?
 pH scale - Test the pH of things like coffee, spit, and soap to determine whether each is acidic,
basic, or neutral. Visualize the relative number of hydroxide ions and hydronium ions in
solution. Switch between logarithmic and linear scales. Investigate whether changing the
volume or diluting with water affects the pH. Or you can design your own liquid!
 Salt and Solubility - Add different salts to water, then watch them dissolve and achieve a
dynamic equilibrium with solid precipitate. Compare the number of ions in solution for highly
soluble NaCl to other slightly soluble salts. Relate the charges on ions to the number of ions in
the formula of a salt. Calculate Ksp values.
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APS Science 2011
Videos
Prentice Hall “Chemistry Alive! Field Trips”
 Chemistry of Soft Water
 The Story of Suds
 Cool Clear Water
Discovery LearningEducation (www.discoveryeducation.com)
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Elements of Chemistry: Acids, Bases and Salts- Acids and bases are two different classes of
compounds that are fundamental to the functioning of our world. When they combine, acids
and bases produce salts. Students explore the chemistry of acids and bases and focus on the pH
scale, an ingenious measurement of the amount of acidity and basicity of compounds. The
program concludes by illustrating how the level of acids and bases contribute to processes as
varied as acid rain and the functioning of the cells in our bodies (9 segments, 20:00)
Chemistry Connections: Explaining the Strengths of Acids and Bases- An experiment
comparing acidic solutions in relationship to their pH and conductivity leads to a definition of
strong and weak acids. A similar procedure is followed for bases. Students develop equilibrium
expressions for acids and bases and the Ka and Kb are then used to define strong and weak
acids and bases. [5 segments, 29:05]
Chemistry Connections: Acid-Base Indicators - Common substances are used to reveal how and
why indicators change color in the presence of acids or bases. Demonstrates universal
indicators and universal indicator strips. Students are challenged to design an experiment that
determines the relative pH of several solutions using only indicators. Industrial uses for
indicators are examined as well. [5 segments, 29:05]
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Field Trips
 Outdoor Lab – Health of the Stream at the outdoor lab. pH and Water testing kits
Other
 None noted.
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