Chapter 12 Solutions
Chapter Opener
__Chapter Overview, TE Review the objectives listed in the Student Edition.
Section 1 Types of Mixtures
PACING: 90 minutes
PENNSYLVANIA ACADEMIC STANDARDS FOR SCIENCE AND TECHNOLOGY:
3.2.A.2 Know that science uses both direct and indirect observation means to study the world and the
universe;
3.2.A.3 Integrate new information into existing theories and explain implied results;
3.2.B.1 Describe materials using precise quantitative and qualitative skills based on observations;
3.2.B.2 Develop appropriate scientific experiments: raising questions, formulating hypotheses, testing,
controlled experiments, recognizing variables, manipulating variables, interpreting data, and producing
solutions;
3.2.B.3 Use process skills to make inferences and predictions using collected information and to
communicate, using space / time relationships, defining operationally;
3.2.C.2 Evaluate the appropriateness of questions;
3.2.C.4 Conduct a multiple step experiment;
3.2.C.5 Organize experimental information using a variety of analytic methods;
3.2.C.6 Judge the significance of experimental information in answering the question;
3.4.A.8 Apply knowledge of mixtures to appropriate separation techniques.
Objectives
1. Distinguish between heterogeneous and homogeneous mixtures.
2. List three different solute-solvent combinations.
3. Compare the properties of suspensions, colloids, and solutions.
4. Distinguish between electrolytes and non-electrolytes.
FOCUS (5 minutes)
__ Lesson Starter, TE Help students understand how mixtures can be classified by particle
size.
MOTIVATE (10 minutes)
__Discussion, TE Ask students to list common solvents found in their homes.
TEACH (65 minutes)
__PowerPoint
__Visual Strategy, Figure 2, TE Use the models in this figure to establish the difference
between solutes composed of electrolytes and solutes composed of nonelectrolytes.
__Demonstration, TE Use a solution of water and ethanol and a solution of water and sugar
to show that the same volume of solute in the same volume of solvent will not always
make the same volume of solution.
__Table Strategy, Table 1, Some Solute-Solvent Combinations for Solutions, TE Have
students identify specific common examples of solutes and solvents that are solid, liquid,
or gas.
__Application, TE Discuss the emulsifying properties of lecithin.
__Table Strategy, Table 2, Classes of Colloids, TE Have students think of common
examples of the different types of colloids.
__Table Strategy, Table 3, Properties of Solutions, Colloids, and Suspensions, TE Have
students predict whether the components of the solutions on this table can be separated
by filter paper or centrifuge.
__QuickLab, Observing Solutions, Suspensions, and Colloids, SE Have students inspect
seven different mixtures and classify them as solution, suspension, or colloid.
__Datasheet for In-Text Lab, QuickLab Observing Solutions, Suspensions, and
Colloids, ANC Students use the datasheet to complete the QuickLab.
__Visual Strategy, Figure 5, TE Have students inspect this figure and suggest reasons why
aqueous solutions with electrolyte solutes conduct electricity and solutions with nonelectrolyte solutes do not.
__Chapter Lab, Microlab, Separation of Pen Inks By Paper Chromatography, SE
Students practice the separation of mixtures by the method of paper chromatography.
__Datasheet for In-Text Lab, Separation of Pen Inks By Paper Chromatography, ANC
Students use the datasheet to complete the Chapter Lab.
__Pre-Lab, Paper Chromatography, ANC
__Datasheet for In-Text Lab, Pre-Lab Paper Chromatography, ANC Students use the
datasheet to complete the Pre-Lab.
__Skills Practice Experiment, A Close Look at Soaps and Detergents, ANC
__Inquiry Experiment, Paper Chromatography, ANC
__Inquiry Experiment, What’s So Special About Bottled Drinking Water?, ANC
__Forensic and Applied Science Experiments: The Athletic Rivals Students use paper
chromatography to match the ink from a pen to the ink extracted from a threatening note.
CLOSE (10 minutes)
__Section Review, SE Students answer end-of-section vocabulary, key ideas, critical
thinking, and interpreting graphics questions.
__Alternative Assessment, TE Have students construct a concept map that includes the
terms heterogeneous mixture, homogeneous mixture, solution, colloid, and suspension.
OTHER RESOURCE OPTIONS
__Study Guide, Section Review
__Section Quiz
__Using the Handbook, TE Have students read in greater detail about alloys from the
Elements Handbook.
Section 2 The Solution Process
PACING: 90 minutes
PENNSYLVANIA ACADEMIC STANDARDS FOR SCIENCE AND TECHNOLOGY:
3.4.A.8 Apply knowledge of mixtures to appropriate separation techniques.
Objectives
1. List and explain three factors that affect the rate at which a solid solute dissolves in a
liquid solvent.
2. Explain solution equilibrium, and distinguish among saturated, unsaturated, and
supersaturated solutions.
3. Explain the meaning of like dissolves like in terms of polar and nonpolar substances.
4. List the three interactions that contribute to the enthalpy of solution, and explain how
they combine to cause dissolution to be exothermic or endothermic.
5. Compare the effects of temperature and pressure on solubility.
FOCUS (5 minutes)
__ Lesson Starter, TE Use a demonstration in which you add FeCl2 to three beakers of
water. Stir the FeCl2 into one beaker, crush the FeCl2 before you add it to another beaker,
and merely put the FeCl2 and water together in a third beaker, to demonstrate properties
that affect dissolution.
MOTIVATE (10 minutes)
__Application, TE Discuss how hot packs and cold packs rely on endothermic and
exothermic reactions.
TEACH (65 minutes)
__PowerPoint
__Reading Skill Builder, Prediction Guides, TE Ask students for their opinions regarding
several assertions about solubility, and record them for later discussions as the chapter
progresses. (BASIC)
__Demonstration, TE Use a solution of glucose in water to discuss solution saturation and
solution equilibrium.
__Visual Strategy, Figure 7, TE Students should recognize that even though a system
appears stable, there is activity at the particle level.
__Visual Strategy, Figure 8, TE Students should notice that solutions can be unsaturated
over a range of solute masses.
__Demonstration, TE Use seeding of a supersaturated solution to demonstrate precipitation
of a solute
__Table Strategy, Table 4, Solubility of Solutes as a Function of Temperature, TE Have
students use this table to determine whether solubility increases or decreases as
temperature rises.
__Demonstration, TE Compare the characteristics of warm water and cold water to
enhance understanding of solution behavior.
__Visual Strategy, Figure 9, TE Students should notice that the orientation of water
molecules changes depending on which ion they surround. (ADVANCED STUDENTS)
__Visual Strategy, Figure 10, TE Have students decide whether the water in hydrates is a
solute or a solvent. (ADVANCED STUDENTS)
__Visual Strategy, Figure 11 and Figure 12, TE Students should recognize the difference
between phase and state from these two figures. (ADVANCED STUDENTS)
__Application, TE Discuss Henry’s Law and its application to nitrogen narcosis and “the
bends” in scuba divers.
__Visual Strategy, Figure 14 and Figure 15, TE Have students describe how the solubility
of different substances is affected by temperature, using the data in these figures.
__Application, TE Discuss the use of sodium nitrite and sodium nitrate as preservatives.
__Table Strategy, Table 5, Enthalpies of Solution, TE Ask students to use this table to
determine whether dissolving AgNO3 in water would increase or decrease the
temperature of the system
__Careers in Chemistry, Environmental Chemist, SE Students can extend their
knowledge of chemistry by reading about the responsibilities of an environmental
chemist.
__Cross-Disciplinary Connection, Artificial Blood, SE Students can read about the
development of molecules with specific properties to fulfill specific needs.
__Teaching Strategy, Artificial Blood, TE Point out to students that a surfactant is used as
a “bridge molecule” to enable the nonpolar perfluorocarbons to mix with the polar saline
solution.
__Discussion, Artificial Blood, TE Have students find out more about the different
functions performed by blood.
__Microscale Experiment, Relative Solubility of Transition Elements, ANC
CLOSE (10 minutes)
__Section Review, SE Students answer end-of-section vocabulary, key ideas, critical
thinking, and interpreting graphics questions.
__Alternative Assessment, TE Have students draw a picture of the dissolution process.
OTHER RESOURCE OPTIONS
__Study Guide
__Section Quiz
__Chemical Content, EXT Go to go.hrw.com for a full-length feature on how surfactants
make nonpolar and polar compounds soluble.
__Graphing Calculator, Predicting Solubility from Tabular Data, EXT Go to
go.hrw.com for a graphing calculator exercise that asks you to predict the solubility of a
substance at various temperatures.
__CBL Probeware Lab, Effect of Temperature on Solubility of a Salt, EXT Go to
go.hrw.com for this CBL probeware lab.
Section 3 Concentration of Solutions
PACING: 90 minutes
PENNSYLVANIA ACADEMIC STANDARDS FOR SCIENCE AND TECHNOLOGY:
3.1.B.3 Apply mathematical models to science and technology.
Objectives
1. Calculate the concentration of a solution, given the mass of solute and volume of solvent.
2. Determine the amount of solute in a given amount of solution, given the concentration of
the solution.
3. Determine the amount of solution that contains a given amount of solute, given the
concentration of the solution.
FOCUS (5 minutes)
__ Lesson Starter, TE Using different concentrations of potassium permanganate,
demonstrate how the color varies with concentration.
MOTIVATE (10 minutes)
__Motivation Strategy Share with students some information about the masses of sugar
in several popular soft drinks (obtainable from the Internet) and ask students to
calculate the sugar concentrations, or vice versa.
TEACH (65 minutes)
__PowerPoint
__Problem Solving Workbook, Chapters 15 and 16, ANC Students study sample
problems and practice problems involving solutions and dilutions. (ADVANCED
STUDENTS)
__Sample Problem A, SE Demonstrate how to find the molarity of a solution from mass
and volume
__Sample Problem B, SE Demonstrate how to determine the number of moles in a solution
from volume and molarity
__Sample Problem C, SE Demonstrate how to find the volume of a solution that will
contain a given mass of solute when you know the molarity of the solution.
__Practice Problems C, SE Students find the molarity of a solution from mass and volume,
determine the number of moles in a solution from volume and molarity, and find the
volume of a solution that will contain a given mass of solute.
__Visual Strategy, Figure 18, TE Have students compare and contrast the procedure to
prepare a 0.5 molar solution with the procedure to make a 0.5 molality solution.
__Sample Problem D, SE Demonstrate how to find the concentration of a solution, given
the masses of solute and solvent.
__Sample Problem E, SE Demonstrate how to determine the mass of solute needed to
prepare a solution with a given molar concentration.
__Practice Problems E, SE Students find the concentration of a solution, given the masses
of solute and solvent, and determine the mass of solute needed to prepare a solution with
a given concentration.
__Math Tutor, Calculating Solution Concentration, SE Students use the relationships
discussed in the chapter to practice concentration calculations.
__Microscale Experiment, Testing Reaction Combinations of H2 and O2, ANC
__Forensic and Applied Science Experiments: The Untimely Death Students use
interpolation and Beer's Law to determine the concentration of a solution. (ADVANCED
STUDENTS)
CLOSE (10 minutes)
__Section Review, SE Students answer end-of-section vocabulary, key ideas, critical
thinking, and interpreting graphics questions.
__Alternative Assessment, TE Have students prepare a flow chart or concept map that
describes how to prepare a solution of specified molarity.
OTHER RESOURCE OPTIONS
__Study Guide, Section Review
__Section Quiz
__Additional Sample Problems, TE Demonstrate how to find the molarity and molarity of
solutions and how to use molarity to determine the volume needed to prepare a given
solution.
__Additional Practice Problems, EXT Students can practice more problems asking them to
calculate molarity and molality.
End of Chapter Review and Assessment
PACING: 45 minutes
__Chapter Review, SE Students answer questions organized by section and as a mixed
review.
__Chapter Test A, Solutions
OTHER RESOURCE OPTIONS
__Standardized Test Prep, SE Have students complete the standardized test prep to help
them prepare for standardized tests.
__SciLinks Visit www.scilinks.org, maintained by the National Science Teachers
Association, for information on Solutions, Colloids, Electrolytes/Nonelectrolytes, and
Solubility.
__CNN Video, CNN Presents Science in the News: Chemistry Connections Segment 14,
Harvesting Salt; Segment 24, Mixing Oil and Water; and Segment 25, Multivitamins