Essay on Biology Lab Report

Submitted By template2
Words: 578
Pages: 3

Part 1- Testing for Diffusion: A Guided Activity
Summary of experiment: The point of the experiment was to see how diffusion works and what it effects. The experiment is tested to see if the solution would be either starch or glucose.
Answers of analysis questions:
-The starch remains in the dialysis bag because the molecules are bigger than the pores. Also because there is no blue on the outside of the tape.
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- record the data every 5 minutes or so to get more data and you can see the diffusion progress until it finishes.
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Part 2- Osmosis Investigation: A Guided Activity
Summary of experiment: The point of the experiment was to see the relationship between water and solutes.
Data Table:
Solution
Initial Mass
Final Mass
Mass Diff.
% Change
Distilled Water
30.31g
32.84g
2.53g
8.3%
0.2 M Sucrose
27.9g
29.9g
2g
7.2%
0.4 M Sucrose
28.6g
31.4g
2.8g
9.8%
0.6 M Sucrose
29.2g
32g
2.8g
9.6%
0.8 M Sucrose
33.6g
36.8g
3.2g
9.5%
1.0 M Sucrose
36.1g
39.4g
3.3g
9.1%

Answers of analysis questions:
- The solute is hypertonic and water moves into the bag. When the molarity increases, water will move within the bag.
- If the solutions were placed in 0.4 M sucrose solution, then all the masses will be lighter than they are and some of them will be isotonic and hypertonic.
- using percentage is a useful way to compare unequal values. Absolute values can only be relevant when comparing two samples of equal mass.
- answer: -10%

- The sucrose solution in the beaker would have been hypotonic to the distilled water in the bag.
Part 3- Osmosis Activity: An Inquiry Activity
Summary of experiment: The point of the experiment was to see which solutions would be hypertonic solutions and which ones would be hypotonic solutions.
Hypothesis: If you put different solutions in distilled water, then 3 of them (glucose, sucrose and egg white) will be hypotonic solutions, NaCl would be hypertonic and the distilled water would be isotonic.
Independent and Dependent Variables:
Independent Variable: Types of Solutions
Dependent Variable: Time in the water to change the mass.
Procedure:
1. Get following materials: 5 solutions (Glucose, Sucrose, NaCl, Egg White, and Distilled Water), 5 plastic tubes, 5 cups filled with distilled water, a scale and 10