Procedure I - Test Solution 1: 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	1.38	1.33	1.33	0
2	1.28	2.12	1.70	1.70	0

[1] Given that the final heights (and volumes) are the same forthe water and test solution, what can you conclude about the amountof solutes in these two solutions? Explain your reasoning.

[2] As discussed in the Background material, water is animportant biological molecule. Do you expect water to continue toflow across the semipermeable; lipid bilayer after osmoticequilibrium is reached? Why or why not?

Procedure II - Test Solution 2: Guanine solution

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	1.35	0.88	1.75	-0.87
2	1.28	2.03	1.22	2.09	-0.87

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

[4] What do you think would happen if both starting volumes werethe same? Test your hypothesis by doing a data run. Explain yourobservation.

[5] Why is the difference in final volumes the same (or veryclose to the same) for both trials?

Procedure III - Test Solution 3: Cytochrome C solution

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	1.52	1.07	1.73	-0.66
2	1.28	2.05	1.33	2.00	-0.67

[6] Based on your data and observations from procedure II andprocedure III, which solution has the highest concentration?Explain your answer.

[7] Concentration Calculation: Using your Trial 1 data fromprocedure II and procedure III, and the known concentration ofguanine (see Activity Form tab), calculate the concentration of thecytochrome c solution. Hint: See the Summary of Needed Formulassection under the Background tab and information found under theActivity Form tab.

Solution	Compound	mMolarConcentration (mmol/L)
solution2	guanine	0.170
solution3	cytochrome c	to bedetermined

Note: Concentration is a measure of the amount of a substancecontained per unit volume. A commonly used unit for the amount ofsubstance is the mole (mol). When used along with the metric unitfor volume, concentration may be expressed in mole per liter(mol/L). Often, for the small concentrations associated withbiological systems, millimole per liter (mmol/L) may be used toexpress concentrations. One millimole is 1/1000 of a mole.