Gummy Bear Osmosis

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Gummy Bear Osmosis
Name ___________________________________
Date ______
Period ____________ Seat ______
Diffusion is defined as the movement of molecules from an area of high concentration to an area of low
concentration. The diffusion of water molecules through a selectively permeable membrane is known as
osmosis. Movement through membranes is called transport. Diffusion and osmosis are passive forms of
transport; this means that they do not need energy to move from areas of high concentration to areas of
low concentration. Active transport requires energy to transport molecules from low concentration to
high concentration.
Question: How will soaking Gummy Bear candies in distilled water affect their size?
Prediction (explain your prediction based on the background information):
Materials: (Groups of 3)
Plastic cup (1)
Gummy Bears (3 of different colors)
Metric ruler
Distilled water
Electronic balance
Calculator
Figure 1
Procedure:
Day 1
1. Use a pen to label your cup with your names & class period.
2. Obtain three different colored Gummy Bears.
3. Use a ruler to measure the length, width, and height of
each Gummy Bear in centimeters, ±0.1cm (see Figure 1).
Record these measurements in your data table on page 2.
4. Calculate the volume (in cm3) of each Gummy Bear and record
these values in your data table.
5. Use an electronic balance to find the mass (in grams) of
each of your Gummy Bears. Record these masses in your data table.
6. Use a marker to divide the bottom of your cup into three
equal zones. Place a letter in each zone that represents the
colors of your Gummy Bears (see Figure 2)
7. Fill your cup with distilled water (NOT tap water)
8. Lay each Gummy Bear in the cup within its corresponding zone.
9. Leave the Gummy Bears in the water overnight.
length
Figure 2
R
G
W
R = red
G = green
W = white
1
height
width
O = orange
Y = yellow
B = blue
Gummy Bear Osmosis
Name ___________________________________
Date ______
Period ____________ Seat ______
Part 2: The next day
1. After the Gummy Bears have been in distilled water overnight, GENTLY take one Gummy Bear out
of the water and pat it dry.
2. Use your ruler to measure the length, width, and height (in cm) of the Gummy Bear. Record these
values in your data table under the correct Gummy Bear color.
3. Calculate the volume (in cm3) of the Gummy Bear and record this value in your data table.
4. Use an electronic balance to find the mass (in grams) of your Gummy Bear. Record this value in
your data table.
5. Repeat steps 1-4 with the other two Gummy Bears.
Data
Dimensions
Gummy Bear #1
(Color:_______________)
Initial
Final
Before
After
Soaking
Soaking
(Day 1)
(Day 2)
Gummy Bear #2
Gummy Bear #3
(Color:______________) (Color:_______________)
Initial
Final
Initial
Final
Before
After
Before
After
Soaking
Soaking
Soaking
Soaking
(Day 1)
(Day 2)
(Day 1)
(Day 2)
Length (cm)
Width (cm)
Height (cm)
Volume (cm3)
LxWxH=
Mass (grams)
Questions and Analysis:
1. What type of solution (hypertonic, isotonic, or hypotonic) did you place the Gummy Bear in, and
what happened to the Gummy Bear as a result of being placed in the solution (Look at your Day 1
vs. Day 2 results)? Explain the direction of water movement.
_________________________________________________________________________________
_________________________________________________________________________________
_________________________________________________________________________________
_________________________________________________________________________________
2. What do you think will happen if the Gummy Bears were placed in salt water on day 2 and left in the
salt solution until day 3?
_________________________________________________________________________________
_________________________________________________________________________________
________________________________________________________________________________
2
Gummy Bear Osmosis
Name ___________________________________
Date ______
Period ____________ Seat ______
3. Before soaking the Gummy Bears in distilled water, the distilled water tested negative for glucose.
Now perform a glucose test using Benedicts solution on the water that the bear was soaking in.
a. What were the results? _____________________________________________________
b. Show me the results for credit. __________________ (my initials)
c. Explain why glucose (is/isn’t) found in the soaking water: _______________________
________________________________________________________________________
Calculate the percent change in the size of the candy:
4.
% Change in Volume
Gummy Bear #1
( _____________
After soaking volume
Gummy Bear #2
Gummy Bear #3
˗ _____________ )
Before soaking volume
( _____________
˗ _____________ )
After soaking volume
Before soaking volume
( _____________
˗ _____________ )
After soaking volume
Before soaking volume
_______________ x 100 = _______%
Before soaking volume
_______________ x 100 = _______%
Before soaking volume
_______________ x 100 = _______%
Before soaking volume
Average % Change in Volume
( _______________% + ________________% + _________________% ) / 3 = _______________%
% change of bear #1
5.
% change of bear #2
% change of bear #3
% Change in Mass
Gummy Bear #1
( _____________
After soaking mass
Gummy Bear #2
( _____________
After soaking mass
Gummy Bear #3
( _____________
After soaking mass
˗ _____________ )
Before soaking mass
˗ _____________ )
Before soaking mass
˗ _____________ )
Before soaking mass
_______________ x 100 = _______%
Before soaking mass
_______________ x 100 = _______%
Before soaking mass
_______________ x 100 = _______%
Before soaking mass
Average % Change in Mass
( ________________% + ________________% + ________________% ) / 3 = _______________%
% change of bear #1
% change of bear #2
% change of bear #3
3
Gummy Bear Osmosis
Name ___________________________________
Date ______
Period ____________ Seat ______
6. Graph the average percent changes on a bar graph. Remember to title and label both axes.
7. Conclusion: Write a conclusion for this controlled experiment.
In your conclusion, be sure to:
 Answer the experimental question.
 Include supporting data from your data table.
 Explain how this data supports your conclusion.
 Provide a scientific explanation for the trend in the data.
Question: How does soaking Gummy Bears in distilled water affect the size of the candy?
4
Gummy Bear Osmosis
Name ___________________________________
Date ______
Period ____________ Seat ______
Plan a controlled experiment to answer the question below. You may use any materials and equipment
in your procedure.
Be sure your procedure includes:
• Logical steps to do the experiment
• Two controlled (kept the same) variables
• One manipulated (independent) variable
• One responding (dependent) variable
• How often measurements should be taken
and recorded
Question: How is the volume of the Gummy Bears affected by the percent salt water solution they are
placed in?
5
Gummy Bear Osmosis
Name ___________________________________
Date ______
Period ____________ Seat ______
Conclusion Scoring Rubric
Attributes
Conclusive statement:
Supporting data for Percent change in Volume:
Supporting data for Percent change in Mass:
Explanatory language:
Scientific explanation:
Total Attributes and Score Points
Attribute Name
Credit
Description / Evidence of Attribute
Controlled Variables
(need at least two)
Manipulated Variable
Responding Variable
Record Measurements
Trials are Repeated
Extra Validity Measure
Logical Steps
Total Attributes
Score Points
6
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