Question

Data Table II Note: Difference in Final Volumes = Final Volume of Test Sol - Final Volume of Water

Trial	Starting Volume of Test Solution (L)	Starting Volume of Water (L)	Final Volume of Test Solution (L)	Final Volume of Water (L)	Difference in Final Volumes (L)
1	1.28	1.78	1.96	1.10	.86
2	1.28	2.28	2.21	1.35	.86

[3] Why did the height (and volume) change in the test solution? What is the basis for the increase in the volume in the test solution?

Answer 1

In this case, I will assume that we are studying the phenomenon of osmosis and that the Test solution can be hypotonic or hypertonic with respect to the water. Additionally, both, the water and test solution are separated by a semipermeable membrane.

In this context, remember that in osmosis, the water will flow from the solution with less concentration of solution to the concentration with the highest solute concentration. In trial number 1, the water lost water. At the beginning, the water volume was 1.78 and at the end it was 1.10. This means that the test solution was much more concentrated than the side with only water. The same happens in trial 2, where the initial volume of water was 2.28 and the final volume was 1.35.