HASPI Medical Chemistry Lab Draft
Reaction Rates Round Robin
Teacher Information
NGSS/Common Core State Standards
Students who demonstrate understanding can:
HS-PS1-5. Apply scientific principles and evidence to provide an explanation about 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.]
Science and Engineering Practices
Disciplinary Core Ideas
Crosscutting Concepts
Constructing Explanations and
Designing Solutions
Constructing explanations and
designing solutions in 9–12 builds
on K–8 experiences and progresses
to explanations and designs that
are supported by multiple and
independent student-generated
sources of evidence consistent with
scientific ideas, principles, and
theories.
 Apply scientific principles and
evidence to provide an
explanation of phenomena and
solve design problems, taking
into account possible
unanticipated effects.
PS1.B: Chemical Reactions
Chemical processes, their rates, and
whether or not energy is stored or
released can be understood in terms
of the collisions of molecules and
the 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 kinetic
energy.
Patterns
Different patterns may be
observed at each of the scales at
which a system is studied and can
provide evidence for causality in
explanations of phenomena.
Connections to other topics in this grade-level:
HS.PS3.A
Articulation across grade-levels:
MS.PS1.A; MS.PS1.B; MS.PS2.B; MS.PS3.A ; MS.PS3.B (HS-PS1-5); MS.PS3.D
Common Core State Standards Connections:
ELA/Literacy RST.11-12.1
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.
WHST.9-12.2 Write informative/explanatory texts, including the narration of historical events, scientific procedures/
experiments, or technical processes. )
Mathematics MP.2
Reason abstractly and quantitatively.
HSN-Q.A.1
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.
HSN-Q.A.3
Choose a level of accuracy appropriate to limitations on measurement when reporting quantities.
Interpretation & Description
In this lab students will explore the effect of Surface Area, Temperature, Stirring, Catalysts, Enzymes
and Concentration on how a medication reacts. The specific description of the medical application is
found on each station, however reaction rate is a key concept in the study of Pharmaceuticals as it
can affect how a medication works, its effectiveness, its degradation, the possibility of overdose and
much more.
This is a Round Robin activity where students will find a different variable at each station.
Place the directions in a plastic sleeve at each station and hand out the answer sheet for students to
bring to each station. At the station they will first read the background and medical application and
answer questions about it. They will then hypothesize about the potential outcome of the lab. They
will do the listed procedure, writing their observations as they go. Finally they will create a concluding
sentence that specifies what they learned at that station.
Station 1: Surface Area involves students running two reactions using Alka Seltzer tablets and water.
Students will increase the surface area of the Alka Seltzer tablet by grinding it up in one reaction and
leave the other whole. The effects of surface area on the rate of a chemical reaction can be applied
to differences in “time-release” medications.
At Station 2: Temperature students will run another pair of reactions with Alka Seltzer tablets and
water. One reaction will use room temperature water while the other uses warm water that has been
heated on a hot plate. The effects of temperature on the rate of a chemical reaction can be applied to
the importance of storing certain drugs at specific temperatures. If certain drugs are not stored at
proper temperatures they will break down quicker, greatly affecting their efficacy.
Station 3: Stirring & Mixing involves students comparing two reactions between Sodium Bicarbonate
(Baking Soda) and vinegar. One of the reactions will be left alone while the other will be stirred with a
stirring rod. The effects of stirring & mixing on the rate of a chemical reaction can be applied to the
importance of muscle contraction in the breakdown of food and absorption of nutrients throughout the
digestive system.
At Station 4: Catalyst students are asked to make observations of the breakdown of Hydrogen
Peroxide (H2O2) in a container all by itself and in a container with a platinum catalyst. The container
and catalyst that are used at this station are the same as the ones found in contact lens cleaning kits.
The medical background at this station, as well as Station 5: Enzymes, gives insight to the destructive
properties of Hydrogen Peroxide, which is a very common compound in the human body.
Station 5: Enzymes also involves the breakdown of Hydrogen Peroxide. Students will read more
about the destructive properties of H2O2 and how the human body has enzymes like catalase to
counteract those destructive properties. At this station students will add common foods that contain
catalase ( garlic, potato, and spinach) to H2O2 to see what effect it may have on the rate of reaction.
Station 6: Concentrations involves running two Alka Seltzer reactions in soapy water. In one container
students will only add 1/3 of a tablet while the other will contain 2/3 of a tablet. The effects of
concentrations on the rate of chemical reactions can be applied to figuring out the correct dosage of
medications and running the risk of an overdose.
Allow for up to 5 minutes to have students read the background and answer questions, then 5 more
minutes for the lab and analysis. You may use a 5 minute timer to keep students on track, and so
that all students move at the same time.
Learning Target
By the end of class students will be able to observe and predict the changes in reaction rates with
changes in
 surface area
 temperature
 molecular motion
 concentrations,
 applications of catalysts and enzymes.
Time
Actual Time (please make note below)
Estimated Time
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



Station 1: Surface Area – 10-15 minutes
Station 2: Temperature – 10-15 minutes
Station 3: Stirring & Mixing - 10-15 minutes
Station 4: Catalysts - 10-15 minutes
Station 5: Enzymes - 10-15 minutes
Station 6: Concentration - 10-15 minutes
* allow 5 minutes to read and answer questions, then 5 minutes to do the lab and respond. You can
easily cut out stations if you are limited on time, or do the lab over more than one class period.
Note: Share the actual time on forum (www.haspi.org) or at HASPI curriculum conference
Materials
Station 1 Surface Area
2 250mL beakers
1 mortar and pestle
1 tablet of Alka-Seltzer per
group
200mL water per group
Station 2 Temperature
2 250mL beakers
1 large hot plate
1 tablet of Alka-Seltzer per
group
200 mL Water per group
Station 3 Stirring
2 125mL Erlenmeyer
flasks
Balance
small weigh boat
1.5 g sodium bicarbonate
per group
stirring rod
100mL of Vinegar per
group
Station 4 Catalyst
2 50mL beakers
1 ClearCare or similar
contact case with platinum
disc
50mL of Hydrogen
Peroxide per group
Station 5 Enzymes
8 test tubes
Mortar and Pestle
Potato
Spinach
Garlic
10mL Hydrogen peroxide
per group
Station 6 Concentration
2 100mL graduated
Cylinders
Soapy Water
1 Alka-Seltzer per group
*Make the soapy water
ahead of time by adding
dish soap to water and
mixing.
You will need a total of
Supply
Provided (P)
or Needed
(N)
Quantity
Company/
Item #
Approximate
Cost
Station 1: Surface Area
Alka Seltzer Tablets
P
30 packs
of 2
Mortar and pestle
P
2
Sodium bicarbonate
P
30 g
Vinegar
P
2000 mL
Hydrogen Peroxide
P
1000 mL
Soapy Water
P
2000 mL
Water
N
100mL x 4
Spinach
N
1 bag
Potato
N
20 1/2 inch
cube
pieces
Garlic
N
20 1/2 inch
cube
pieces
250 mL beaker
N
4
50 mL beaker
N
4
125 mL Erlenmeyer flask
N
4
Balance
N
2
Hot Plate
N
2
100mL graduated cylinder
N
4
Test Tubes
N
8
Small weigh boat
N
2
Stir rod
N
2
Graduated Cylinder
N
2
Common Student Misconceptions
Additional Misconception Notes:



Students may have trouble making a hypothesis. You will want to talk about how to make a
testable hypothesis, provide them with the possible hypotheses, or provide sentence starters.
o You may want to have a class discussion and write out all hypothesis possible and have
students pick one.
Students can have trouble differentiating between dissolving and reacting. You might review the
different signs of a chemical reaction and talk about the bubbles as proof of a reaction.
You can also discuss the specific reaction between Alka-seltzer and water. Alka-Seltzer contains
citric acid and sodium bicarbonate. By dissolving them in water they can come into contact and
react with each other.
Guiding Questions
Many guiding questions are in the "pre-lab" portion of this lab. This means the lab can be done at
any point in the unit. As an inquiry activity the students will get a preview of the concepts they will
learn, or you can do the lab after teaching the concepts in order to solidify their understanding.
Key idea/questions to discuss:
 What causes a reaction?
 Have students write out and balance each reaction that occurs.
 What signs provide evidence for a reaction taking place?
 What variables change reaction rate?
 What mechanisms can speed up/slow down reaction rates? Why would you want to speed
up/slow down reaction rates?
 Compare and contrast the words catalyst and enzyme.
 Explain the difference between catalyst and inhibitor.
 Discuss the difference between the rate of a reaction and the amount of reaction that takes
place.
Additional Information
Information
Page #
Location
Resources and References
http://antoine.frostburg.edu/chem/senese/101/consumer/faq/why-does-alkaseltzer-fizz.shtml
Images (in order of appearance)
http://antoine.frostburg.edu/chem/senese/101/consumer/faq/why-does-alkaseltzer-fizz.shtml