Egg Osmosis Lab Sheet

Problem:

1.  Which solution is a hypertonic, hypotonic, and isotonic solution and how does it affect a cell using osmosis? (What do you expect to happen to the weight of the eggs in each?)

Background Info:

Hypotonic / Isotonic / Hypertonic
Define: / Define: / Define:

Form 3 Testable Hypotheses (one for each solution): I predict that, if (MV), then (RV), because…

1.  ______

2.  ______

3.  ______

Experiment:

Materials: (For each group of students.)

-  3 eggs - 300ml vinegar

-  4 clear, 40oz plastic cups - 100ml saltwater

-  3 pleated sandwich bags - 100ml distilled water

-  A sharpie marker - 100ml(g) corn syrup

-  graduated cylinder - triple beam balance

Procedures:

Day 1 – Removing the shell (Everyone)

1.  See class copy of procedures.

2.  Record observations about what is happening to the egg in vinegar. (See Day 1 – Observations)

Day 6 – Assessing the change in our eggs after vinegar.

1.  See class copy of procedures.

Day 11 – Assessing the change in our eggs after the 3 solutions.

1.  See class copy of procedures.

Collect Data: mass of cup: ______

Liquid / Amount of Liquid (ml) / Mass of Egg (g)
Before / After / Before / After
Vinegar / E1 100ml / E1 / E1 / E1
E2 100ml / E2 / E2 / E2
E3 100ml / E3 / E3 / E3
Corn Syrup
Distilled Water
Salt Water

Day 1- (Observations) What can be inferred about the cause of the bubbles?

Day 6-

E1 / E2 / E3
Change in Mass (g)
Change in Vinegar (ml)
How do they look?

Day 11-

E1 / E2 / E3
Change in Mass (g)
Change in Liquid (ml)
How do they look?

Data Analysis:

1.  Use a bar graph to show how each solution affected the egg’s mass. (RV = mass of egg, MV = type of liquid. You will have 2 bars for each solution: one bar for the egg’s initial mass and the second bar for its mass after it has been in the solution).

Draw Conclusions: (On this paper, answer the following questions. Attach additional paper.)

Paragraph 1 - Restate the problem and each of your hypotheses.

Paragraph 2 - Summarize your procedures. Be specific but don’t recopy them word for word.

Paragraph 3 - Explain how the MV affected the RV. (What does the graph show?)

a.  Example: The bar graph shows that when the E1 was placed in corn syrup, the mass of the egg ______. The change in mass for E1 after being placed in the corn syrup for 6 days was ______. (Do this for all 3 eggs.)

Paragraph 4 - Explain whether or not the results supported your hypothesis.

a.  The data collected shows that when E1 was placed in the corn syrup, the mass ______. This happened because______(explain the changes of the egg’s mass in terms of osmosis).

This proves/disproves my hypothesis. (Why/why not?)

Paragraph 5 - Future experiments.

a.  Explain questions you may have had during this experiment. What other questions about osmosis would you like to test? In the future I would ______.

______

______

______