Lesson Sequence Planning Length of lesson sequence: Three weeks
Essential Question:
How can the collision theory may be used to explain the decomposition of hydrogen peroxide used to
estimate the concentration of household bleach through a simple reaction and the action of a catalyst?
(student goals: to understand the effects of changing the temperature or concentration of the reacting
particles on the rate at which a reaction occurs?) [Clarification Statement: Emphasis is on student reasoning that focuses on the number
and energy of collisions between molecules.] [Assessment Boundary: Assessment is limited to simple reactions in which there are only two reactants; evidence from
temperature, concentration, and rate data; and qualitative relationships between rate and temperature.]
Cross Cutting Concept
Science & Engineering Practices- Skill
What skills does the student need to complete Disciplinary Core Idea - Topic
Chemical processes, their rates, and whether or not energy
the SEP?
•
provide an explanation of
•
is stored or released can be understood in terms of the
collisions of molecules and the
Apply scientific principles and evidence to
phenomena and solve design problems,
taking into account possible unanticipated
effects
Different patterns may be observed
at each of the scales at which a
system is studied and
can provide evidence for
rearrangements of atoms into new molecules, with
consequent changes in the sum of all bond energies in the
set of molecules that are matched by changes
in
causality in explanations of
phenomena.
kinetic energy.
Students are Engaged: What is going to be used to engage students?
What is happening? Why do you think this is happening? Check for prior knowledge. (see 5E handout)
https://www.youtube.com/watch?v=C5tOEBmBAHg
Iodine Clock reaction
https://www.youtube.com/watch?v=1TWAR1KtYJU
I Didn't Know That - Blowing Up an Airplane Tire
Students Explore(What are the TOOLS used by students to explore):
Reading:
Suggested Grouping
Catalyst in Living Organisms Enzymes
http://www.rsc.org/learn-chemistry/resource/res00000815/enzymes-and-jellies?cmpid=CMP00000909
http://www.absorblearning.com/chemistry/demo/units/LR1506.html
http://www.hhmi.org/biointeractive/lactose-digestion-infants
http://www.hhmi.org/biointeractive/natural-selection-lactose-tolerance
Catalyst Speed up reactions and Inhibitors slow down a reaction
http://www.chem4kids.com/files/react_catalyst.html
http://sciencelearn.org.nz/Contexts/Nanoscience/Sci-Media/Video/Catalytic-converters-and-platinum-nanoparticles
Effect of temperature changes in reaction rates
http://www.middleschoolchemistry.com/multimedia/chapter6/lesson4
http://study.com/academy/lesson/rate-of-a-chemical-reaction-effect-of-temperature.html?seekTo=1:10
https://archive.org/details/DrMattJCarlsonScienceTheaterEp005Temperature_0
Concentration changes and reaction rates
http://www.docbrown.info/page03/3_31rates3a.htm
http://www.kentchemistry.com/links/Kinetics/FactorsAffecting.htm
Hydrogen Peroxide and its use
http://www.ch.ic.ac.uk/rzepa/mim/environmental/html/h2o2_text.htm
http://www.h2o2.com/municipal-applications/drinking-water-treatment.aspx?pid=123
– Evidence to
support claim
How does it make sense? How does it connect?
Patterns
http://www.diyncrafts.com/10960/health/51-extraordinary-everyday-uses-for-hydrogen-peroxide
Bleach
https://www.rhfs.com/pulse/thermoplastics-solve-the-challenges-of-water-disinfection-using-sodium-hypochlorite/
http://www.oxy.com/OurBusinesses/Chemicals/ResponsibleCare/Documents/Sodium%20Hypochlorite.pdf
Video:
Hydrogen Peroxide Videos
https://www.youtube.com/watch?v=NN2tHSkcObk
https://www.youtube.com/watch?v=NI4uL4JN51c
https://www.youtube.com/watch?v=uZCCwWx0Z0o
Bleach Videos
https://www.youtube.com/watch?v=seOe1ythYbQ
Writing: Informational Essay answering the essential question with citations to supportive evidence.
Hands-on: Three experiments to obtain data and understand reaction rates. Estimating the concentration of bleach by determining its conductivity, measuring oxygen gas pressure,
measuring the oxidation reaction potential change and concentrations
Titration and conductivity of Bleach
http://www2.vernier.com/sample_labs/CHEM-I-19-redox_titrations_open.pdf
Estimating the concentration of Bleach reacting with Hydrogen Peroxide
http://www.rsc.org/learn-chemistry/resource/res00001729/estimating-the-concentration-of-bleach?cmpid=CMP00005243
Reaction Rates of Hydrogen Peroxide
http://www.vernier.com/files/sample_labs/CHEM-I-22-reaction_rates_open.pdf
Students Explain (What key concepts students should be able to explain?)
guided Questions to explain real situations:
The Theory of Kinetic Energy.
The Collision Theory.
What factors influence the frequency of collisions of reactant molecules?
Why do these factors influence reaction rates?
What is the rate of reaction?
How does the collision theory describe rates and changes in rates of chemical reactions?
What is the role a catalyst plays in increasing the reaction rate? How is that achieved?
What is the role of activation energy in a chemical reaction?
How can potential energy diagrams be used to determine if a chemical reaction is endothermic or exothermic?
Students Elaborate (what activities can students do to expand, enrich, and connect/apply to real world situations)
Students can learn about Lactose intolerance and enzyme mediated reactions.
Students can learn about how catalytic converters work and why are do they have a high price.
Students Generate and Evaluate Evidence (Students able to communicate what they have experienced, explored, and learned):
Students construct an explanation that includes the idea that as the kinetic energy of colliding particles increases and the number of collisions increases, the reaction rate
increases.
Students identify and describe evidence to construct the explanation, including: i. Evidence (e.g., from a table of data) of a pattern that increases in concentration (e.g., a change in
one concentration while the other concentration is held constant) increase the reaction rate, and vice versa;
Student evaluates the evidence of a pattern that increases in temperature usually increase the reaction rate, and vice versa.
Student integrates evidence, facts, and scientific principles to construct the explanation:
a) Molecules that collide can break bonds and form new bonds, producing new molecules.
b) The probability of bonds breaking in the collision depends on the kinetic energy of the collision being sufficient to break the bond, since bond breaking requires energy.
c) Since temperature is a measure of average kinetic energy, a higher temperature means that molecular collisions will, on average, be more likely to break bonds and form new
bonds.
d) At a fixed concentration, molecules that are moving faster also collide more frequently, so molecules with higher kinetic energy are likely to collide more often.
e) A high concentration means that there are more molecules in a given volume and thus more particle collisions per unit of time at the same temperature.
1.
2.
3.
Completing a full lab report on the GC experiment and the performance on the laboratory procedure.
Completing note assignments
Writing an essay in response to the essential question; with citations.
4.
Performance Expectations rubric
Teacher Formative Assessment (what types of questions would you ask your students throughout the activity to determine if
they learned the lesson) differentiation
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"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
Teacher Summative Assessment performance on NGSS Evidence Statements, ELA and Math Standards
ELA Standards:
California Common Core State Standards Connections: ELA/Literacy
Cite specific textual evidence to support analysis of science and technical texts, attending to important distinctions the author makes and to any gaps or inconsistencies
in the account. (HS-PS1-5)
Conduct short as well as more sustained research projects to answer a question (including a self-generated question) or solve a problem; narrow or broaden the inquiry
when appropriate; synthesize multiple sources on the subject, demonstrating understanding of the subject under investigation. (HS-PS1-3)
Write informative/explanatory texts, including the narration of historical events, scientific procedures/ experiments, or technical processes. (HS-PS1-5)
Draw evidence from informational texts to support analysis, reflection, and research. (HS-PS1-3)
Math Standards: Reason quantitatively and use units to solve problems. (HS-PS1-5)
Use units as a way to understand problems and to guide the solution of multi-step problems; choose and interpret units consistently in formulas; choose and interpret
the scale and the origin in graphs and data displays. (HS-PS1-5)
Choose a level of accuracy appropriate to limitations on measurement when reporting quantities. (HS-PS1-5)