# Osmosis Lab

In Glogpedia

Last updated 4 years ago

Discipline:
Science
Subject:
Biology
8,9,10,11,12

What I think will happen?

IDV : Molarity of the solution originally within each bagDV : Percent change in each bag's final mass

Osmosis Lab

In this lab we tried to answer the question: How does the concentration of a solute within a cell affect the percent of its mass gained or lost after osmosis?As a class, we found that a higher original molarity usually causes a greater percentage of the orignal mass to be gained by the cell. Biologically, these results occurred because water moved through the membrane towards the solute (which was only within the cell and therefore had a greater concentration there). The cell had a hypertonic relationship with its environment.Two sources of error which afected our class average include the presence of strings on the "cell" and not leaving enough room for expansion. The strings on the ends of the tubing absorbed the water from the beaker, so when measuring the final mass, the contained water would add an incorrect value. The instruction to "Leave sufficient space for the expansion" does not instruct specifically for each molarity, so if there was not enough space for full expansion, the final mass would be lower than it should have been in a realistic environment. We could fix each of these errors by drying the strings carefully and leaving more time to dry. This would reduce the amount of water contained in the strings ( and therefore reduce the error's magnitude). The issue of expansion space could be solved by specific instructions for the estimated amount of space needed for each solution to expand properly. The solutions would then be able to fully interact with the environment and portray more accurate patterns/results.

Conclusion

Data Tables and Graphs

Questions

1. Each bag's initial mass was different, so the percent change is a more accurate way to compare results and find a pattern (rather than comparing the mass value gained).

2. 20g-18g 18g * 100 = approx. 11.1% change in mass

3. It would flow out of the tubing and into the sucrose solution.