Lesson Plans

Chemistry: The Central Science 9th Edition ©2003

by Brown, LeMay, and Bursten

Weeks 14–15: Solution Properties

Chapter 13: Properties of Solutions

Covering the concepts will not take the allotted two weeks, but there are a huge number of problems that students must tackle in order to understand these concepts.

College Board Performance Objectives:

• Describe the energy changes associated with the formation of a solution and the role of entropy.
• "Like dissolves like!"
• Effects of temperature and pressure on solubility.
• Define units of concentration, mass percent, ppm, mole fraction, molarity, molality, and be able to calculate each from appropriate data.
• Be able to convert a concentration from one unit to the other.
• Describe the effect of solute (or solvent) concentration on each colligative property—vapor pressure, boiling point, freezing point, osmotic pressure. Be able to calculate any of these effects from concentration data.
• Calculate the concentration and molar mass of a nonvolatile, nonelectrolyte from its effect on a colligative property.
• Explain the difference in magnitude of these effects caused by electrolytes compared to nonelectrolytes. Define the van't Hoff factor, i.
• Become familiar with the types of colloids.

College Board Lab Objectives:

• Become familiar with one of the colligative properties and use it to determine the molar mass of a substance.

Suggested Labs:

• Experiment 19, Colligative Properties: Freezing-Point Depression and Molar Mass, p. 203.

Resources:

• Instructor's Resource Manual, pp. 159–174
• Student's Guide, pp. 268–287
• Test Bank, pp. 474–505
• Instructor's Resource CD, Chapter 13

Pacing Guide:

• Solution Process—1 day
• Solubility and Factors Affecting It—1 day
• Concentration: M, m, %, w/w, ppm, mole fraction—3 days
• Colligative Properties: Vapor Pressure, Boiling Point, Freezing Point, and Osmosis—4 days
• Colloids—.5 day
• Block Scheduling
  Discuss Solution Process, and Solubility and Factors Affecting It in the first block. A lot of time (nearly two blocks) in this lesson will be spent working problems involving calculating concentrations of solutions in the various units and the converting of the units. Colligative Properties calculations will require another two blocks. It is critical that students work all of the suggested problems! Spend very little time with Colloids, mainly by defining the terms used in dealing with them.

Key Words:

Suggested Exercises:
Critical thinking questions and end-of-chapter activities are included in these exercises.

• pp. 518–523, # 1, 3, 7, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31, 33, 35, 37, 39, 41, 43, 45, 47, 49, 51, 53, 55, 57, 59, 61, 63, 73, 76, 79, 82, 85, 89, 96.
• eMedia Exercise: p. 523, # 101, 102.

Troubleshooting Tips/Error Traps:

• An extensive number of exercises have to be done in this lesson in order for students to learn the concepts and skills that are necessary.