CHE1020
Spring 2014
TO: Professor Michelle Sama
FROM: Taylor Fitzgerald, CIT Student
LAB PARTNER: Sam Brissette
DATE: January 21, 2014
SUBJECT: How to Think Like a Scientist: Chemical Changes
Purpose: To perform and gain an understanding of chemical reactions by
performing a blue bottle reaction.
Summary: Synopsis of the essential information you gained by doing the lab.
One or two sentences to tell the client what you discovered. Note that it’s harder
to be concise than to ramble on, so this will take some effort.
Procedures:
There are two parts to the “How to Think like a Scientist: Chemical
Changes” lab: Part 1 is the reaction and part 2 is the experimental part. During
part 1, fill a clean 125 mL Erlenmeyer flask approximately 2/3 full of tap water,
then mark the water level with a wax pencil or piece of tape. Add 0.6 grams of
ascorbic acid and record the mass to the nearest 0.01 grams. Next, add 1 drop
of methylene blue. Put the stopper in the flask and shake until the solution is
mixed. Now add 4 drops of cupric sulfate, and then replace the stopper again.
Once the stopper is in place, shake the solution for 20 seconds and record times
and observations. After shaking the flask for 20 minutes, let the solution set for
a few minutes and record any further observations. You will repeat shaking the
solution for 20 seconds 3 more times.
For part 2, the next step is to brainstorm questions that could be
experimental. Once a hypothesis is formulated, you apply your question by
experimenting. An example that was suggested is, “What happens with a
different amount of water?”. Now that the hypothesis has been decided on,
repeat the same steps as part 1, but putting the groups’ suitable steps towards
the experiment.
Results:
Part II Science Inquiry
Groups
Question
Result
Arden and Maria
What happens if the flask is
1/3 of the way filled with
water?
What will occur if the flask if
filled with more than 2/3 of
water?
The solution fades much
faster with less water.
Mary and Kim
Asha and Kristin
What happens with a
different amount of ascorbic
Color changes still occur, but
it takes a longer amount of
time. The blue color takes
longer to darken each time it
is shaken.
Color fades slower after being
shaken.
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CHE1020
Spring 2014
Laura and Hallie
acid (0.8 g)?
How does the number of
shakes in 20 seconds effect
the color of the liquid?
Taylor, Matt, and Jason
What happens if the amount
of methylene blue is doubled?
Andrew and Eme
What if we double the
ascorbic acid? Will it stay
darker longer?
What happens if you add 8
drops of cupric sulfate?
Joe, Mark, and Marry
Sam and I (Taylor)
What happens if the cupric
sulfate was decreased to 2
drops? Would the change from
blue to clear be slower?
The more the liquid is
agitated, the darker the color
and the longer it takes to go
clear.
It makes a darker blue but the
solution still goes clear after
setting.
The solution went from a
darker color to a light color
faster.
The solution does not turn as
dark of a blue after you shake
it.
The solution takes
approximately 2-2.5 mores
times longer to change from
blue to clear.
Once the class has successfully completed both parts 1 and 2 of the lab, there
was a table created with the partners’ names, the new hypotheses, and the
results received by each group.
Commentary: Here is your chance to “spin” your results to the reader and try to
get them to see it your way. However, it’s important to include comparisons as
well. Were your results similar to those of other groups? Where results what you
expected? Why or why not? Think about errors that were beyond your control,
and think about how you could have improved the experiment or your
performance.
Attachments: Note that all attachments should be clearly labeled and concise,
and should refer to related sections of the memo.
1) Raw data – required but reviewed only when necessary
2) Sample calculations – required by reviewed only when necessary
3) Notes: Any other information you think might help me understand your
results and report. Optional, but may help your grade.
Pointers for getting a great grade:
 Write the memo in the past tense
 Mention or explain calculations
 Mention how you could improve the experiment
 Discuss error and its sources
 Provide a written summary of your results
 Be sure to attach raw data and sample calculations as attachments
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