Quantities in Chemistry
Practical Work/ Mini-Lab
(Dayana, Robin, Kin)
As a group, we decided to come up with the “Awesome Bubble Gum Lab” as an
interactive lab activity that would further asses and broaden students’ understanding of
the mole concept since students are asked to calculate the number of moles of sucrose
and particles consumed while chewing a piece of gum.
Placement in Course, Teacher Knowledge and Skills Needed
This lab has to be placed after a few topics that have been taught in the Quantities in
Chemistry chapter. The students should be comfortable knowing the Avogadro’s number
and the concepts between moles and molar mass, as well as moles and particles. This lab
fits in perfectly with the chapters’ “Big Idea” of knowing essential/basic knowledge of
calculating “Chemistry” (one might say).
For this experiment, we would ask the students a day prior to the lab, to practice their
conversions between particles and mass. This would help further prepare the students for
the lab since they will be encountering several questions that require previous knowledge
of conversions. Hence, this will allow them to be more efficient while conducting,
gathering, calculating and analyzing data in the lab
In this lab, the teacher should know the basic calculations for converting mass to moles
and moles to particles and vice versa. The benefits of this lab are as follows,
1) There is a scarce amount of safety measures that must be taken into consideration
2) not much material is required
The teacher should make sure to outline basic sanitary rules which ask students to dispose
properly of all gum materials into the garbage bins and to not reuse (chew) gum
previously used by another colleague.
Preparation and Skills (including Safety Issues)
For this lab, (depending on the students), we would make the mole bridge on the
blackboard for those students who are confused or were absent during the lesson covered
previously on moles and mole conversions. The lab handout clearly outlines all of the
instructions in a simplified manner so that students could follow The procedure section
has enough details along with the table included for students to be on track.
As stated before, this lab is extremely efficient since it does not have many safety
precautions.
Laboratory Set-up and Diagram
If the experiment was going to be done in Room 322 with 24 students, it would be
important to have students work together in groups of twos. As for the lab itself, the
materials used are minimal and not much chemicals are used. In this lab, the materials
required would be several electronic balancers and stops watches. If there were few
balancers, we would tell the students to take turns to weigh out the bubble gum. As for
the bubble gum itself, we would have a full bucket, so we do not run out. Any left over
gum could be given to all students as a treat for their great effort during the lab activity.
Student Instructions
See Mini-Lab Handout
Questions relating directly to the Lab:
The Awesome Bubble Gum Experiment!!!
Introduction:
How much sugar is in a piece of bubble gum? How quickly is this sugar consumed by
chewing? In this experiment, assume that all the mass lost by chewing a piece of bubble
gum is sucrose. The chemical formula for sucrose is C12H22O11 and 1 mole contains 6.02
x 1023 molecules of sucrose.
Experiment:
Materials:
 Electronic balance

2 pieces of bubble
gum

1 stop watch
Procedure:
1. Obtain 2 pieces of bubble gum
2. Weigh the bubble gum with the wrapper on the electronic balance
3. Unwrapped one of the gums and weigh the wrapper on the electronic balance
4. Record the mass of the gum in trial one
5. Chew the gum
6. With a stop watch, time how long it will take the sugar to disappear in your mouth
7. Record the time in trail one
8. Now weigh the chewed gum on the electronic balance with the wrapper
9. Record this final mass in trial one
10. Determine the mass differences of the gum for trial one
11. Repeat steps 2-10 for trial 2
12. Take the average mass difference and time for each trial
Trail
Table 1. Time and mass for each double bubble gum
Mass of Mass of Mass
Mass
Mass of
Mass
gum + wrapper
of
after
gum
difference
wrapper
(g)
gum chewing
after
of gum
(g)
(g)
gum +
chewing
(g)
wrapper
(g)
(g)
1
2
Average
Analysis & Communication:
1. What is the average mass of sucrose in grams that you consumed?
2. How many moles of sucrose did you consume?
3. How many molecules of sucrose did you consume?
Time
(s)
4. How many molecules per second of sucrose did you consume?
5. What sources of error exist in this experiment?
Sample Student Answers
Trail
Table 1. Time and mass for each double bubble gum
Mass of Mass of Mass
Mass
Mass of
Mass
Time
gum + wrapper
of
after
gum
difference
(s)
wrapper
(g)
gum chewing
after
of gum
(g)
(g)
gum +
chewing
(g)
wrapper
(g)
(g)
6.3
0.5
5.8
3.8
3.3
2.5
180
1
6.8
0.58
6.22
3.4
2.82
3.4
240
4.2
210
2
Average
Analysis & Communication:
1. What is the average mass of sucrose in grams that you consumed?
The average mass of sucrose that I have consumed is 4.2 grams.
2. How many moles of sucrose did you consume?
MC12H22O11 = ((12 x 12.01)) + (22 x 1.01) + (11 x 16.00)) = 342.34 g/mol
m= 4.2 grams of C12H22O11
N C12H22O11 = m/M = 4.2 g C12H22O11 x 1mol C12H22O11 = 1.23*10-2 mol of C12H22O11
342.34 g
Therefore, I consumed 1.23*10-2 moles of sucrose.
3. How many molecules of sucrose did you consume?
N C12H22O11 = 1.23*10-2 moles
Avogadro’s number = 6.022*1023 molecules = 1 mol
# of molecules of sucrose = 1.23*10-2 mol C12H22O11 x 6.022*1023 molecules
1 mol
= 7.40 *1021 molecules of C12H22O11
Therefore, I consumed 7.40 *1021 molecules of sucrose.
4. How many molecules per second of sucrose did you consume?
Rate of consumption (molecules/ second) = 7.40 *1021 molecules of C12H22O11
210 seconds
= 3.52 *1019 molecules of C12H22O11 per
second
Therefore, I consumed 3.52 *1019 molecules of sucrose in 210 seconds.
5. What sources of error exist in this experiment?
-
Presence of saliva on gum
Assessment/Evaluation of Student Achievement
For this experiment, we will be mainly using the cooperative learning as our strategy.
This strategy allows students of different cognitive levels to work together to help
improve each others’ understanding of the subject being studied while accomplishing the
purpose or goal of the lab. Students will be asked to work in groups of twos on executing
the lab and answering the questions listed above. However, even though each student is
given the opportunity to discuss and share answers with one another, each student is
accountable for handing in their own work. We proposed to use such strategy since it
allows students to share their strengths and to develop their weaker skills. The
implementation of such strategy enhances students’ social skills and will further develop
their understanding of the topic covered. This strategy will be implemented throughout
the experiment since students will be given instructions to read the lab, discuss the lab,
collect data, analyze data and then answer the questions in groups of twos. Students’
understanding of the lab will be assessed through the answers that they provide for the
analyses and communication questions outlined in the lab.