Question

3.06 The Cool Egg Lab

The effects of different concentration solutions on the
movement of water
Problem/Question: Can we observe the movement of water
into or out of a selectively permeable membrane by
changing the concentration of the external solution?
Procedure:
Day 1 - Chicken egg placed in vinegar
1. Find the mass of a raw egg. Record this in the table below.
3. Measure 80mL of vinegar in a graduated cylinder. Pour
into cup with egg.
4. Note any reactions taking place. Record your observations
in data table 1.
Day 2 - Vinegar removed and replaced with corn syrup
Hypothesis for Day two (What will happen to the mass of the
egg in corn syrup and distilled water? Explain why?):
5. After 48 hours describe any changes you notice about the
egg or the vinegar. Gently touch the egg with your finger and
note changes. Record in table 1.
6. Carefully mass the egg in the cup. Make sure you record
JUST the egg's mass.
Data Table 1: Change in the Egg's mass over time
Egg mass in grams Describe the egg
Day 1 (vinegar)
Day 2 (Corn syrup)
Day 2 (Distilled water)
4 CaCO3 + C₂H4O₂ 4 Cat² + 2 H₂O + 6 CO₂
Questions and Analysis
1. Describe the differences in the shell of the egg from Day 1
to Day 2. Explain what you think caused the difference in the
egg shell? Use the equation above to explain.

Answer 1

The Cool Egg Lab utilizes osmosis to demonstrate the movement of water through a selectively permeable membrane in response to concentration gradients of solutions.

Step-by-step explanation:

The student's Cool Egg Lab aims to observe the movement of water through a selectively permeable membrane, which is a process known as osmosis. In the provided experiment, a dialysis-tubing bag with 5% lactose and 5% fructose was introduced into distilled water. After some time, fructose was detected outside the bag, but lactose was not. This tells us that fructose molecule size allows it to pass through the membrane, unlike the larger lactose molecules.

In the context of the egg experiment, the shell's weight changes are due to the reaction of the eggshell with vinegar, represented by the chemical equation provided in the question, and the subsequent osmotic movement of water on the following days when exposed to corn syrup and distilled water. When the egg is placed in corn syrup, a hypertonic solution relative to the egg content, water will move out of the egg to balance the concentration gradient, which is why the egg mass is expected to decrease. Conversely, placing the egg in distilled water, which is hypotonic to the egg's interior, would result in water moving into the egg, hence the mass would increase.

The osmotic movement occurs until an equilibrium is reached, and this process can be demonstrated using other setups such as U-tubes with a semipermeable membrane between two solutions of different concentrations as illustrated in the references.