Lesson Plans

Chemistry: The Central Science 9th Edition ©2003

by Brown, LeMay, and Bursten

Weeks 16–17: Chemical Kinetics

Chapter 14: Chemical Kinetics

College Board Performance Objectives:

• Express the rate of a reaction in terms of changes in the concentration of a reactant or a product per time. Understand how to change from one to the other.
• Understand the difference graphically between average rate and instantaneous rate. Be able to calculate both.
• Explain the meaning of the reaction rate law and the rate law constant.
• Be able to determine a reaction rate law for a reaction from experimental data.
• Calculate the rate law constant (including units) after finding the rate law constant from experimental data. After this, calculate the rate of another experiment not included in the data.
• Understand what is meant by order in terms of a reactant as well as the overall order.
• Explain graphically the concept of activation energy and how temperature affects reaction rate.
• Understand how temperature affects the rate law constant for a reaction.
• Be able to relate the collision model to all of the above.
• Explain what is meant by a reaction mechanism and know the meaning of elementary steps, rate-determining step, and intermediate species.
• Be able to explain and show how a rate law is derived from a certain reaction mechanism.
• Describe the theory of how a catalyst works.

College Board Lab Objectives:

• Experimentally measure the rate of a reaction.
• Measure the effect of the concentration of a reactant on the rate.
• Determine the order with respect to this reactant.
• Obtain the rate law for the reaction from the data.

Suggested Labs:

• Experiment 27, Rates of Chemical Reactions I, p. 311
• Experiment 28, Rates of Chemical Reactions II, p. 325

Resources:

• Instructor's Resource Manual, pp. 175–192
• Student's Guide, pp. 288–310
• Test Bank, pp. 506–538
• Instructor's Resource CD, Chapter 14

Pacing Guide:

• Rate of Reaction and Its Measurement—1 day
• Concentration and Reaction Rate Law (Order and Rate Law Constant)—3 days
• Temperature, Collision Theory, and Activation Energy—2 days
• Reaction Mechanisms and Rate-Determining Step—2 days
• Catalysis—1 day
• Block Scheduling
  During the first block, make sure that students understand what reaction rate is, and how it can be measured in terms of different species. Concentration and Reaction Rate Law will require the better part of two blocks. If time permits, begin teaching the effects of temperature, which will probably require another block. Reaction Mechanisms and Rate-Determining Step is a very difficult concept to grasp and will take most of a block to cover. Students need only read the section on catalysts.

Key Words:

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

• pp. 564–573, # 1, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 37, 53, 55, 57, 59, 61, 63, 65, 75, 78, 80, 91.
• eMedia Exercise: p. 573, # 101, 102.

Troubleshooting Tips/Error Traps:

• A reaction's reaction rate law cannot be determined from the overall stoichiometric equation unless the reaction has a one-step mechanism.
• Reaction mechanisms must be in terms of concentrations of original reactants, not intermediates.
• Temperature has a twofold effect on rate; it increases the frequency and effectiveness of collisions between reacting molecules.