Osmosis Lab

By: Marty Madar

Introduction

Osmosis is the movement of water in or out of a cell to equalize the solute concentrations on both sides, the solution and the object. In osmosis water can move into the solution from the object or into the object from the solution. A hypertonic solution is when water moves out the object and into the solution. A hypotonic solution is when water moves out of the solution and into the object. Osmosis is a form of passive transport which means it doesn't require energy. Osmosis works to maintain homeostasis in a cell. Homeostasis is when your body is in a state of equilibrium and is under stable internal conditions.


This lab was created to demonstrate how osmosis works. It's supposed to show how hypertonic and hypotonic solutions work. It will show what happens when an object is placed in a solution that has a higher or lower concentration.


The independent variable of this experiment would be the type of solution. The dependent variable would be the mass of the dialysis tube, which is what's measured. The control variables are the amount of water in the tube, the amount of solution poured into the cup, and how long the dialysis tube is left in the solution.

Hypothesis

If the solution contains more solutes than the dialysis tube, the mass of the dialysis tube will decrease. If the solution contains less solutes than the dialysis tube, the mass of the dialysis tube will increase.

Materials

-3 dialysis tubes

-Liter of drinking water

-Liter of distilled water

-Liter regular dark soda

-Liter dark diet soda

-String

-A balance

-3 cups

-Writing utensil

Procedure

1) Tie one end of three dialysis tubes with string.

2) Add 10 mL of drinking water to the three tubes, then tie the other ends.

3) Add 200 mL of regular soda into one cup, 200 mL of diet soda to another cup, and 200 mL of distilled water into another cup.

4) Measure the mass of three dialysis tubes with the balance and write them on the side of the cup and in a data table.

5) Place one tube in each of the three cups.

6) Let it sit for 24 hours.

7) Remove the tubes and measure the mass again.

8) Record the differences.

Results

The mass of the dialysis tube in the diet soda before placed in the soda was 11.11 grams and then went down to 10.76 grams after 24 hours inside the diet soda. The mass of the dialysis tube in the regular soda before was 11.83 grams and then decreased to 8.15 grams. The dialysis tube in the purified water before was 9.87 grams and after was 10.01 grams.

Conclusion

As indicated earlier, the hypothesis is If the solution contains more solutes than the dialysis tube, the mass of the dialysis tube will decrease. If the solution contains less solutes than the dialysis tube, the mass of the dialysis tube will increase. The hypothesis was true. When the dialysis tube was placed in diet and regular soda, water moved out of the dialysis tube because there were more solutes in the soda than in the dialysis tube. The water moves towards the place that has a higher solute concentration which was the soda. These are hypertonic solutions. That's why the mass decreased. When the dialysis tube was placed in distilled water, water moved into the dialysis tube because there more solutes in the drinking water than the distilled water, which is the solution. This is a hypotonic solution. So according to this experiment, water tends to move towards where the highest solute concentration is in the process of osmosis.