# AP Biology Lab 2 ```Osmosis Lab
Purpose:

To investigate the effect of solute concentration on osmosis as it relates to living plant tissues.
Background: Research what osmosis is and various osmotic solutions. Make sure to cite your
resource(s) in MLA or APA format.
Hypothesis: Write in if, then form.
Materials:
Various fruits/vegetables, knife, 5 cups, 5 sucrose solutions, food coloring, labeling tape, digital
balance, calculators, distilled water
Procedure:
1. Use slicing device to cut 6 French fry size pieces of vegetable/fruit.
2. Obtain 5 sucrose solutions in different cups and label.
3. Take initial mass of vegetable/fruit pieces.
4. Place vegetable/fruit pieces in cup for 24 hours.
5. Blot each of the 6 pieces off. Take final mass of pieces. Calculate mass difference and % change
in mass. To calculate: percent change in mass = (final mass-initial mass)/ initial mass. Multiply
Contents in Bag
Initial Mass
Final Mass Mass difference
% Change in
Mass
Distilled Water
0.2 M
0.4 M
0.6 M
0.8 M
1.0 M
ANALYSIS OF RESULTS
Graph data, identify variables and constants! Then answer the following questions in
paragraph form:
1. Explain the relationship between the change in mass and the molarity of sucrose.
2. Why did you calculate the percent change in mass rather than simply using the change in mass?
3. Describe which solutions were hypotonic, hypertonic, and isotonic. Be sure to explain why.
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