Internal Osmosis

COLEGIO INTERNACIONAL DE BOGOTA
IB BIOLOGY SL
Practical Work
Teacher: Ana María Gómez

TOPIC 2.4: MEMBRANES
Osmosis

Objectives:
1. Observe the osmosis process in chicken eggs.
2.Determine the isotonic concentration of a salt and water solution for the egg.
3. Practice statistical analysis and graphical analysis.

Research question:
What is the effect of solutionswith different concentration of salt in the volume of eggs?

Materials (for the whole class):
– 40 chicken eggs, raw
– 3 lt of white vinegar
– 40 transparent plastic cups of 3 ounces– 3200 ml of pure water
– 28 spoonfuls of table salt
– Plastic film

Procedure:
1. Place each egg in a cup and add 60 ml of vinegar. Let them rest three days, while thevinegar decomposes the carbonate shell of the egg.
2. After three days or when the egg shells are completely dissolved rinse the eggs gently with fresh water, measure their volume* (you must describehere the process that you followed to measure the egg’s volume) and place them in an empty and clean cup. Write the measurement in the table, with your initials next to the data.
3. Prepare 8solutions of water and salt using different concentrations, following the amounts in the chart:


|Solution |Pure water (ml) |Amount of salt (spoonfuls) |
|1|400 |0 |
|2 |400 |1 |
|3|400 |2 |
|4 |400 |3 |
|5 |400|4 |
|6 |400 |5 |
|7 |400 |6...