Full Name
Partner’s Full Name
Period #
Baggy Lab – Causes of Observed Chemical Changes
Purpose of the Lab:
Determine which combinations of substances cause the changes observed when the following are
combined: phenol red in water, calcium chloride (CaCl2), and sodium bicarbonate (NaHCO3) (Baking
Soda.
Hypothesis:
An hypothesis is drafted using “If…then…because…” In this lab you will predict what causes each
observed change using only “If…then…” Write your hypothesis below.
Temperature Change:
Gas Production:
Color Change:
Materials:
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


Calcium Chlride (CaCl2)
Sodium Bicarbonate (NaHCO3)
Phenol red dye mixed with water
Water



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Graduated Cylinder
Measuring spoons
Zip lock bags
Goggles
Student Info
Purpose
Procedure (Brief)
Procedure
(Complete)
Procedure (Brief)
Procedure
Procedure A Begin with the overall reaction you saw during the demonstration using the following
steps
1. Lay a zip-lock bag flat on a table
2. Place one teaspoon of calcium chloride in one area of the bag.
3. Place ½-teaspoon of sodium bicarbonate in a separate part of the bag.
4. Measure 5 mL of phenol red solution and pour it into the bag trying to keep it separate from
the other chemicals.
5. Squeeze as much air out of the bag as possible, seal the bag and mix the contents. Write
your observations in the data table.
6.
Procedure B
Provide step-by-step procedures describing what you did in lab to test your hypothesis.
In four or less sentences explain what you did in the lab.
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
Data Table
Table 1:
Observations
Observed Changes
When all chemicals
mixed
Table 2:
Mixture
A1
A2
A3
A4
A5
A6
Substances
Water
+
NaHCO3
Water
+
CaCl2
NaHCO3
+
CaCl2
Phenol Red
+
CaCl2
Phenol Red
+
NaHCO3
NaHCO3
+ Water +
CaCl2
Observations
Observations
HCl (Temp)
HCl (Litmus)
HCl (Observations)
Analysis: Describe in written form, what happened with each chemical combination you used. For
example, “When we mixed sodium bicarbonate, calcium chloride and phenol red in water all
together in one baggy, we observed that…” Use what you wrote in the data table to complete your
analysis.
When we mixed sodium bicarbonate, calcium chloride and phenol red (in water) all together in one
baggy, we observed that
When we only mixed
and
, we observed that
When we only mixed
and
, we observed that
When we only mixed
and
, we observed that
When we only mixed
and
, we observed that
When we only mixed
and
, we observed that
When we only mixed
observed that
and
and
we
Conclusions
Write 4 short paragraphs including
Paragraph 1: Restate your hypothesis and explain why your hypothesis is accepted or rejected. Use
specific examples from your data.
Paragraph 2: What was observed that may have caused the results to be different from what you
expected. Explain any sources of error that may have affected results.
Paragraph 3: Write your ideas for ways to improve this experiment or changes to make it better
Paragraph 4: Use specific examples from your data to answer the question from the beginning of
the lab.