Question

Egg Osmosis

Solution Egg mass (g) Initial Egg mass (g) after 24 hrs Student Observations
Vinegar 45 85 Shell gone; egg seemed swollen and larger
10% Salt water 85 85 No change in egg appearance or size
Kayro Syrup 85 31 Egg was wrinkled and shriveled; much smaller
Distilled Water 85 105 Egg was larger in size; swollen and tight
Students performed an experiment using eggs to observe the effect of osmosis on cells. The egg represented a typical cell. Before beginning the experiment, students soaked the raw eggs overnight in vinegar to remove the shells. What they had in hand, then, was actually a raw, shell-less egg.
Solution concentration can be described in terms of tonicity. Solutions are hypertonic, isotonic, or hypotonic to cells. A hypertonic is one that has a greater concentration of solute outside the cell and therefore a lower concentration. Water will leave the cell and move to the outside environment. This is one reason organisms that live in fresh water cannot survive in salt water, such as the ocean. Water will leave the organism’s cells and eventually the cells will undergo plasmolysis and the organisms will die. An isotonic solution is a balanced solution. That is, the solution concentration is balanced with the solution inside the cell. Finally, when a cell is surrounded by a hypotonic solution, concentration of solute is greater inside the cell, concentration of water greater outside. Water moves into the cell and the cell swells. If enough water enters, the cell can burst.
Procedure: Day 1 – Students found the mass in grams of their shelled eggs, recoding the mass in the data table. The eggs were placed in a beaker and covered with 200 mL vinegar to remove the shells.
Day 2 – The eggs were removed from the vinegar. Visual observations were recorded. The shell-less eggs were wiped dry, massed, and the mass was recorded in the data table. The eggs were placed in a clean beaker and covered with a 10% salt- water solution.
Day 3 – The eggs were removed from the salt water and visual observations were made and recorded. The eggs were wiped dry , massed, and the mass was recorded. The eggs were placed in a clean beaker and covered with sugar (Kayro) syrup.
Day 4 – The eggs were removed from the syrup and visual observations were made and recorded. The eggs were carefully wiped with a damp cloth, massed, and the mass was recorded. The student data was recorded in the data table.
Prior to the start of the experiment, the students hypothesized that both the vinegar and Kayro syrup solutions would be hypertonic to the contents of their eggs. The student data can be seen in the data table above. Does this data confirm their initial hypothesis? Explain.
A) Yes. In both instances, the vinegar solution and Kayro syrup, the egg lost mass.
B) No. The egg in vinegar was an isotonic situation; the egg in syrup was hypertonic as it lost mass.
C) No. The egg in vinegar had an increase in mass therefore vinegar would be hypotonic to the egg's contents.
D) No. The egg in Kayro syrup had a decrease in mass therefore syrup would be hypotonic to the egg's contents.

Answer 1

The vinegar solution was hypotonic as the egg gained mass and swelled, whereas the Kayro syrup was hypertonic as the egg lost mass and shriveled, thus, only part of the students' hypothesis was correct.

Step-by-step explanation:

The student data from the osmosis experiment does not fully confirm their initial hypothesis that the vinegar and Kayro syrup solutions would be hypertonic to the contents of their eggs. The egg in the vinegar solution increased in mass from 45g to 85g, indicating that the vinegar was hypotonic as water moved into the egg, causing it to swell. Conversely, the egg in Kayro syrup decreased in mass from 85g to 31g, which means that the syrup was hypertonic since water left the egg, resulting in it becoming wrinkled and shriveled. Therefore, option C is correct, as it acknowledges the change in mass with vinegar indicating a hypotonic environment for the egg, whereas the syrup created a hypertonic situation where the egg lost mass.