Primary Type: Lesson Plan
Status: Published
This is a resource from CPALMS (www.cpalms.org) where all educators go for bright ideas!
Resource ID#: 51001
Chemical Reaction Rates: Inquiry on Affecting Factors
Chemical reaction rates can differ when different factors are present. The lesson focuses on the main rate changing contributors: temperature,
concentration, surface area, and catalysts. Students are intended to learn through several inquiry based lab stations with minimal teacher guidance.
The labs are of thought and observational base with little complexity in construction.
Subject(s): Science
Grade Level(s): 9, 10, 11, 12
Intended Audience: Educators
Suggested Technology: Interactive Whiteboard,
Overhead Projector, Adobe Flash Player, Adobe
Acrobat Reader, Java Plugin
Instructional Time: 1 Hour(s) 20 Minute(s)
Freely Available: Yes
Keywords: chemical reaction rates, collision theory, temperature, concentration, surface area, catalysts
Resource Collection: CPALMS Lesson Plan Development Initiative
LESSON CONTENT
Lesson Plan Template: General Lesson Plan
Learning Objectives: What should students know and be able to do as a result of this lesson?
Students will observe and explain the factors that affect reaction rates.
Students will explain collision theory by relating chemical reaction to collisions between reacting particles.
Students will follow multistep procedures when carrying out experiments, taking measurements, or performing technical tasks.
Prior Knowledge: What prior knowledge should students have for this lesson?
Students should have an understanding of collision theory.
Students should understand the meaning of "rate" as it pertains to chemical reactions.
Students should understand how to follow directions in a lab setting when working in groups.
Students should know what a catalyst is and its function in chemical reactions.
Guiding Questions: What are the guiding questions for this lesson?
1. Utilize your knowledge of reaction rates to explain why we keep most foods in the refrigerator.
answer:Food that is kept at low temperatures will have low particle movement and the decay process will be delayed. Food left out in hot temperature will
decay much quicker because particle are moving much faster increasing the decay process.
2. Utilize your knowledge of reaction rates to explain why highly concentrated medications can be deadly.
answer: Highly concentrated medication will react much quicker in the body. This will place higher concentrations of the product in the body that your body may
not be able to handle.
3. If the temperature, concentration or surface area were increased in the following scenario, hypothesize how it would change the reaction.
AReactant + BReactant -> Product
answer: The reaction will shift towards the product because the high temperature will cause the reactant to collide much more rapidly changing to the product.
page 1 of 5 Teaching Phase: How will the teacher present the concept or skill to students?
Starting the lesson (duration: 10 Minutes)
Teacher: present students with two glow in the dark sticks. Place one in iced water and one in hot water. Teacher should prompt students to make an observation
and hypothesize why the glow stick is different in each case. Student will respond using their prior knowledge of particle movement and collision theory. If students do
not comprehend the information the visual should be provided utilizing www.freezeray.com.
Teacher should ask questions such as:
"How are the particles behaving at high temperatures vs. low temperatures?"
answer: high temperature more movement faster rate. Low temperature slow movement longer rate.
"How quickly do reactant turn to products for high concentrations vs. low concentration?"
answer: High concentration faster rate products made quickly. Low concentration slower rate reactants take longer to turn to products.
"How does a large surface area vs. a low surface area affect the rate of the reaction"
answer: Larger surface area is reactants turn to product at a faster rate. Smaller surface area reactants turn to product at a slower rate.
Through student teacher discussion it will be feasible to tell how in depth their knowledge of the factors (temperature, concentration, surface area and catalysts) is
and it will allow the educator to further their knowledge through visual representation.
The online simulations is a great tool to discuss the factors, which can increase a reaction rate, and to demonstrate particle behaviors as those factors are applied.
http://www.freezeray.com/flashFiles/RatesOfReactionSurfaceArea.swf
http://www.freezeray.com/flashFiles/RatesOfReactionConc.swf
http://www.freezeray.com/flashFiles/RatesOfReactionTemp.swf
Guided Practice: What activities or exercises will the students complete with teacher guidance?
Prior to starting the inquiry based lab activity the teacher should tell students what each lab station is about and quickly review the procedures for each. The
instructions for each lab station should be printed and pasted at each corresponding group in order for student to follow along individually.
In addition, each student should have a specific role within their group. It is suggested that you have a leader, materials manager, recorder and clean up manager.
Independent Practice: What activities or exercises will students complete to reinforce the concepts and skills developed in the
lesson?
Lab Activity
Students will rotate between four lab stations designed to investigate the four factors temperature, concentration, surface area (particle size), and catalysts which can
change the reaction rates. The student groups should be limited to 3-4 members and each student should be assigned roles.
Station 1 Temperature
Investigate the effect temperature will have on the rate of the reaction. Use anti-acid tablet and two cups of water.
1. In cup A with the iced water add ½ a tablet of anti­acid tablet.
2. In cup B with the hot water add ½ a tablet of anti­acid tablet.
3. Observe which reaction is the quickest.
Questions
A. Which reaction had the fastest rate?
answer: the one in the hot water
B. Explain what could be occurring at the molecular level. (How are the molecules moving or acting?)
answer: the higher temperature allows for more collisions given a product at a faster rate. Hot water gives rapid molecule movement.
Station 2 Surface Areas
Investigate the effect of surface area on the rate of a reaction. Use the steel wool and the lighter (teacher supervision) for the reactions.
1. Ball up pea size amount of steel wool. Burn the piece for 10 seconds.
2. Spread out the piece and make an observation.
3. Burn the spread out piece for another ten seconds.
4. Make an observation.
Questions
A. Which reaction had the fastest rate?
answer: the spread out piece because it gave access to all the molecules which was not the case in the balled up piece.
B. Explain what could be occurring at the molecular level for the balled piece versus the spread out piece. (How are the molecules moving or acting?)
answer: the spread out all molecules are accessible and allows for a faster transition from reactant to product.
C. If left to burn for more than 10 seconds, which would take longer the balled piece or the spread out piece? Explain your answer.
ans: balled piece the molecules are not all accessible causing a longer rate.
Station 3 Concentrations
Investigate the effect of concentration on the rate of a reaction. Use the different concentrations of vinegar and baking soda for these reaction.
1. In one cup use pure vinegar (3mL) and place one spoonful of baking soda.
2. In another cup add pure vinegar (1.5mL) and water (1.5 mL) before you add the spoon full of baking soda.
page 2 of 5 3. Make an observation.
Questions
D. Which reaction had the fastest rate?
answer: the one with the higher concentration
E. Explain what could be occurring at the molecular level in each example. (How are the molecules moving or acting?)
answer: the higher concentration particles are more available tightly fit giving higher probability of collision having reactants turn to product much faster.
F. Why are high concentration reactions faster than low concentrations?
answer: the higher concentration particles are more available tightly fit giving higher probability of collision having reactants turn to product much faster.
Station 4 Catalysts
Investigate the effect of catalysts on the rate of a reaction. Use the catalyst provided with the vinegar and baking soda for these reaction.
1. In small plastic bottle use pure vinegar and place one spoonful of baking soda cover with a balloon.
2. In another small plastic bottle add pure vinegar and add catalysts before you add the spoon full of baking soda covered with a balloon.
3. Make an observation.
Questions
G. Which reaction had the fastest rate
answer: the one with the catalyst
H. Explain what could be occurring at the molecular in each example. (How are the molecules moving or acting?)
answer: the catalyst allows for the reaction to go quicker helping reactants bond to each other faster.
I. How do catalyst cause this effect? (hint: think of the structure of the catalyst)
answer: catalyst's shape allows for them to easy adhere to reactants helping them turn to products at a faster rate without changing the overall reaction.
Closure: How will the teacher assist students in organizing the knowledge gained in the lesson?
Essential questions/guiding questions (10 minutes) Students will respond to one of the essential questions using the knowledge they have gained from their lab
activity. They are encouraged to include the vocabulary for the lesson and give as much detail as possible this will be used to determine their comprehension.
Summative Assessment
Students will conduct small 15 minute experiments that pertain to temperature, concentration, surface area and catalyst's effect on the rate of a chemical reactions.
At the end of the lesson students will choose one of the three main essential questions to assess their understanding. The teacher can determine student
understanding from the lab write-up analysis as well as the student response to the closing essential question.
Station 1 Temperature
Investigate the effect temperature will have on the rate of the reaction. Use anti-acid tablet and two cups of water.
Questions
Which reaction had the fastest rate?
answer: the one in the hot water
Explain what could be occurring at the molecular level. (How are the molecules moving or acting?)
answer: the higher temperature allows for more collisions given a product at a faster rate. Hot water give rapid molecule movement.
Station 2 Surface Areas
Questions
Which reaction had the fastest rate?
answer: the spread out piece because it gave access to all the molecules which was not the case in the balled up piece.
Explain what could be occurring at the molecular level for the balled piece versus the spread out piece. (How are the molecules moving or acting?)
answer: the spread out all molecules are accessible and allows for a faster transition from reactant to product.
If left to burn for more than 10 seconds, which would take longer the balled piece or the spread out piece? Explain your answer.
answer: balled piece the molecules are not all accessible causing a longer rate.
Station 3 Concentrations
Questions
Which reaction had the fastest rate?
answer: the one with the higher concentration
Explain what could be occurring at the molecular level in each example. (How are the molecules moving or acting?)
answer: the higher concentration particles are more available tightly fit giving higher probability of collision having reactants turn to product much faster.
Why are high concentration reactions faster than low concentrations?
answer: the higher concentration particles are more available and tightly fit, giving higher probability of collision: reactants will turn to product more quickly.
Station 4 Catalysts
Questions
Which reaction had the fastest rate?
answer: the one with the catalyst
Explain what could be occurring at the molecular in each example. (How are the molecules moving or acting?)
answer: the catalyst allows for the reaction to go quicker helping reactants bond to each other faster.
How do catalyst cause this effect? (hint: think of the structure of the catalyst)
answer: catalyst's shape allows for them to easy adhere to reactants helping them turn to products at a faster rate without changing the overall reaction.
Essential Questions/ Guiding Questions
1. Utilize your knowledge of reaction rates to explain why we keep most foods in the refrigerator.
answer: Food that is kept at low temperatures will have low particle movement and the decay process will be delayed. Food left out in hot temperature will
page 3 of 5 decay much quicker because particle are moving much faster increasing the decay process.
2. Utilize your knowledge of reaction rates to explain why highly concentrated medications can be deadly.
answer: Highly concentrated medication will react much quicker in the body. This will place higher concentrations of the product in the body that your body may
not be able to handle.
3. If the temperature, concentration or surface area were increased in the following scenario, hypothesize how it would change the reaction.
AReactant + BReactant -> Product
ans: The reaction will shift towards the product because the high temperature will cause the reactant to collide much more rapidly changing to the product.
Formative Assessment
The students prior knowledge of chemical reaction rates and collision theory will be assessed in the first 10 minutes of class where the teacher will utilize the glow in
the dark sticks and www.freezeray.com.
Teacher should ask questions such as:
"How are the particles behaving at high temperatures vs. low temperatures?"
answer: high temperature more movement faster rate. Low temperature slow movement longer rate.
"How quickly do reactants turn to products for high concentrations vs. low concentrations?"
answer: High concentration- faster rate- products made quickly. Low concentration- slower rate- reactants take longer to turn to products.
"How does a large surface area vs. a small surface area affect the rate of the reaction"
answer: Larger surface area - reactants turn to product at a faster rate. Smaller surface area reactants turn to product at a slower rate.
Through student teacher discussion it will be feasible to tell how in depth their knowledge of the factors (temperature, concentration, surface area and catalysts) is
and it will allow the educator to further their knowledge through visual representation.
The online simulations is a great tool to discuss the factors, which can increase a reaction rate, and to demonstrate particle behaviors as those factors are applied.
http://www.freezeray.com/flashFiles/RatesOfReactionSurfaceArea.swf
http://www.freezeray.com/flashFiles/RatesOfReactionConc.swf
http://www.freezeray.com/flashFiles/RatesOfReactionTemp.swf
Feedback to Students
Feedback will be provided the following class period directly on the inquiry lab write ups and on the final guiding questions. Feedback is provided by the teacher and it
should be focused on the students understanding of how temperature, concentration, surface area, and catalysts change particle behavior. Students should also
associate particle movement to collision of particles and the creation of a product.
ACCOMMODATIONS & RECOMMENDATIONS
Accommodations:
Students will be given accommodations according to their Individualized Education Program (IEP). ESOL students should be paired with a peer to aid in translation and
work check. Visual images of steps for the lab can be provided to further understanding of the activity. Emotionally impaired students could be prompted to work
individually or with a familiar peer.
Extensions:
This lesson could be extended to energy diagrams and chemical equilibrium. Teacher could give homework for students to research what the energy diagrams of the
different scenarios would look like. Teacher could ask students to research chemical equilibrium and if it was seen in any of the lab reactions.
Suggested Technology: Interactive Whiteboard, Overhead Projector, Adobe Flash Player, Adobe Acrobat Reader, Java Plugin
Special Materials Needed:
Baking soda
vinegar
steel wool
8 large beakers
2 small graduated cylinders
long stem lighter
distilled water
two hot plates
anti-acid tablets
Catalyst (Any available to you)
4 plastic spoons
2 glow in the dark sticks
2 balloons
2 small empty plastic bottles
Further Recommendations:
The simulations from freezeray.com could be replaced with the Gizmo: Collision Theory
page 4 of 5 (http://www.explorelearning.com/index.cfm?method=cResource.dspDetail&ResourceID=553).
Gizmo is a paid resource that is not available to all counties; However, there is a free 5 day subscription to the program. This program does a great job of showing
particle behavior with all of the four factors specifically with the advantages associated with using a catalyst to speed up the rate.
Additional Information/Instructions
By Author/Submitter
In the surface area lab station, teacher should handle the lighting of the steel wool to prevent fire hazard. In addition, proper lab safety should be used throughout the
duration of the lab.
SOURCE AND ACCESS INFORMATION
Contributed by: Elaine Urdaneta
Name of Author/Source: Elaine Urdaneta
District/Organization of Contributor(s): Miami-Dade
Is this Resource freely Available? Yes
Access Privileges: Public
License: CPALMS License - no distribution - non commercial
Related Standards
Name
LAFS.910.RST.1.3:
Description
Follow precisely a complex multistep procedure when carrying out experiments, taking measurements, or performing
technical tasks, attending to special cases or exceptions defined in the text.
Explain how various factors, such as concentration, temperature, and presence of a catalyst affect the rate of a
chemical reaction.
Remarks/Examples:
SC.912.P.12.12:
Various factors could include: temperature, pressure, solvent and/or solute concentration, sterics, surface area,
and catalysts. The rate of reaction is determined by the activation energy, and the pathway of the reaction can
be shorter in the presence of enzymes or catalysts. Examples may include: decomposition of hydrogen peroxide
using manganese (IV) oxide nitration of benzene using concentrated sulfuric acid hydrogenation of a C=C double
bond using nickel.
page 5 of 5