REACTION RATES
A Science Unit Using Seeing Reason


Classroom Information
Subject Area: Chemistry, physical science
Chemistry, Physical Science
Grade Level(s): 9-12

Standards
Chemistry (grades 9-12)
Reaction Rates
8. Chemical reaction rates depend on factors that influence the frequency of collision of reactant molecules. As a basis for understanding this concept, students know:
a. the rate of reaction is the decrease in concentration of reactants or the increase in concentration of products with time.
b. how reaction rates depend on such factors as concentration, temperature, and pressure.
c. the role a catalyst plays in increasing the reaction rate.
d.* the definition and role of activation energy in a chemical reaction
Learning Objectives
Students will
· Define rate of reaction
· Model (via a causal map) how reaction rates depend on such factors as concentration, temperature, and pressure.
· Demonstrate the role a catalyst plays in increasing the reaction rate
Curriculum-Framing Questions
Essential Question
How does chemistry impact your personal life and society?
Unit Questions
How do chemists control reactions to improve our quality of life?
Content Questions
What is the rate of reaction?
What are the factors which change the rate of a reaction?
What reactions do we speed up or slow down to improve our quality of life?
Seeing Reason Elements (Complete this section if Seeing Reason will be used in this project)
Print Resources for Seeing Reason
Seeing Reason Project Name (For the Seeing Reason workspace)
Reactions!
Project Description (For the Seeing Reason workspace)
The rate of a reaction is the speed at which a reaction happens. If a reaction has a low rate that means the molecules combine at a slower speed than a reaction with a high rate. Some reactions take hundreds, maybe even thousands of years while other can happen in less than one second. Managing the rate of a chemical reaction is critical for a chemist to balance speed verses safety, cost, and productivity. What are all the ways to control the rate of a chemical reaction?
Research Question (For the Seeing Reason workspace)
What changes the rate of a reaction?
Unit Details
This activity comes at the end of the unit – as a culminating experience in lieu of a test question on this topic.
Previously
1. Students will be introduced to reaction rates, factors that can change the rate of a reaction, and some reactions that we’ve had to speed up/slow down to improve our quality of life.
2. They will complete a 2-day lab in which they change reaction rate.
Day 1
1. In triads, students will first be invited to create their causal map on how to change the rate of a reaction. Ideally, all would have computers, with two conducting online research while the third is responsible for recording information on the causal map. SAVE IN PORTFOLIO Criteria: must have at least all kinds of relationships represented
Day 2
2. 20 minutes: Triads will share with another triad. They will share their maps by trading spaces and offering comments in the comment space – being sure to identify themselves by group name.
3. 10 minutes: Triads will return to their map, review comments, and make any revisions that are appropriate. SAVE IN PORTFOLIO
4. 15 minutes: Groups will be asked to group their factors according to: those which are specific to the reactants, and those which are not. They will change colors and location according to this schema. SAVE IN PORTFOLIO Additional Criteria: Reactant-specific factors should be one color, reactant-nonspecific factors should be another.
5. To submit, students will review their report to check for spelling and grammar. When satisfied, they will print out their report for submission.

SRMapImg.gif
Internet Resources
For reaction rates:
Rates
Chemical Kinetics
Reaction Rate (Wikipedia)
Rates of Reaction
Controlling Reaction Rates
Rates of Chemical Reactions
Rates of Reaction Menu
Rates of Chemical Reactions
For fast/slow reactions:
Catalyst
What do we mean by rate?