Using AACT Resources to Teach Kinetics

As chemistry teachers plan activities for their students, AACT will highlight resources from our high school library that help to reinforce topics in different units throughout the school year. Our last news post highlighted resources from our high school library that could be used to support a Thermochemistry and Thermodynamics unit. We will now focus on lessons and other activities that could be used in a Kinetics unit.

Start the unit with one or more of the following demonstrations to help your students visualize what the term “reaction rate” means.

• In the demonstration, Comparing Rates of Reaction, students observe the effect of temperature, concentration, and particle size on the rate of a chemical reaction. This resource includes alignment with NGSS performance expectations and AP Chemistry Big Ideas.
• In the series of demonstrations, Rates of Reactions, students are introduced to factors that affect the rates of chemical reactions. They observe and record their observations, while also describing the rate-influencing factor for each demonstration, as well as evidence supporting whether or not the reaction rate was increased or decreased by the factor.
• In the Simple Kinetics demonstration, students observe that different colors of food dye react with bleach at different rates. They are then challenged to explain their observations and use critical thinking skills. This resource includes alignment with NGSS performance expectations and AP Chemistry Big Ideas.

Then use the Investigating Reaction Rates simulation to give students the opportunity to investigate several factors that can affect the initial rate of a chemical reaction. They also have the opportunity to manipulate several variables including concentration, temperature, or surface area of the reactants as well as the addition of a catalyst during the simulation. The reaction rates are then compared to a controlled reaction. Students interpret a simplified qualitative representation of the reaction as well as analyze corresponding data organized on a graph.

Following the simulation, use one or more of our reaction rate labs to give your students hands on activity to explore reactions.

• Students react Alka-Seltzer tablets with water in the lab, Plop, Fizz: How to Affect the Rate of a Chemical Reaction. By varying the temperature of the water, particle size of the Alka-Seltzer, and concentration of the Alka-Seltzer they will observe the effect on the rate and strength of the chemical reaction.
• Students observe how particle size, solvent temperature, and agitation affect rate of solution in the Rate of Solution lab. This resource includes alignment with AP Chemistry Big Ideas.
• Students explore factors that affect reaction rate and develop a general statement that describes how the factors (temperature, particle size, and concentration) effect the rate based on experimental data with the inquiry-based lab, Reaction Rate.
• Students perform an iodine clock reaction to determine how concentration and temperature effect the reaction rate in the lab, Starch-Iodine Clock Reaction. This resource includes alignment with AP Chemistry Big Ideas.

Then use the demonstration, Catalyst in Motion to allow your students to visualize how a catalyst can impact a chemical reaction. Students also identify the products of a decomposition reaction, as well as determine if the reaction was endothermic or exothermic based on their observations.

Follow the concept of catalysts with the Reaction Mechanisms lesson plan to give students the opportunity to explore reaction mechanisms and their connection to rate laws and energy profile graphs through a game, relay race, and finally a chemical demonstration. This resource includes alignment with AP Chemistry Big Ideas.

For more practice use the Mechanisms and Rate Laws webpage from California State University Dominguez Hills, which provides exercises relating reaction mechanisms to the appropriate rate laws. When you click "New Problem", you will find an overall reaction, the reaction mechanism and the set of possible rate laws. If you miss a problem three times, pressing "Show Answer" will cause the correct answer to appear.

If you teach equilibrium before kinetics, have your students investigate the reaction of the hydrogen sulfite ion (HSO₃^-) and the iodate ion (IO₃^-) to determine the effect that changing concentration and temperature has on the reaction rate with the Kinetics and Equilibrium lab. This resource includes alignment with NGSS performance expectations and AP Chemistry Big Ideas.

Additionally, if you teach both equilibrium and thermochemistry before kinetics, use the lesson plan, Making Connections in Kinetics, Equilibrium and Thermochemistry to show students the connections between the equilibrium constant (K) and the reaction quotient (Q), as well as how they determine the favorability of a reaction. Students also determine if a reaction is kinetically favored or thermodynamically favored. This resource includes alignment AP Chemistry Big Ideas.

If you would like to reiterate some of these concepts, and encourage your students to connect chemical principles to everyday life, use one of the following resources as a culminating activity:

• The Downside to Catalysts - An Exploration of CFC's on the Ozone Layer: In this lesson students make observations of a colorful homogenous catalyst and intermediate in a reaction demonstration that will spark their interests. They then work in teams to analyze graphs and data sets in order to make a real-world connection to AP topics in kinetics such as catalysts, intermediates and reaction mechanisms by exploring how CFCs work to break down the ozone layer. Students also investigate and discuss this environmental issue. This resource includes alignment AP Chemistry Big Ideas.

• Use the Catalytic Converters Video to investigate the role of a catalytic converter and its corresponding chemical reactions within a vehicle. Students learn about both oxidation and reduction reactions and how they, in combination with a catalyst, can impact the molecules released in a car’s exhaust.
• Follow the video with the Catalysis & Catalytic Converters lesson to catalysts to expand student knowledge of chemical reactions and stoichiometry. They first learn about catalytic converters and then are challenged to create the best “catalytic converter” of hydrogen peroxide to oxygen gas in an inquiry-based activity. This resource includes alignment with NGSS standards.

We hope that these activities can help you to reinforce several of the topics covered in a unit about kinetics. Most of these lessons were made possible by great teachers who shared their own resources. We need your help to keep the collection growing. Do you have a great demonstration, activity, or lesson related to this topic that you would like to share with the community? Please send it along for consideration.