Osmosis and Diffusion Lab|
By: Elora Hobbin|
Group Members : Ashley Riley-Roy and Adam Reynolds|
Osmosis and diffusion are two procedures that are critical for cell survival. Diffusion is the movement of molecules from an area of higher concentration to an area of lower concentration. Osmosis is the movement of water molecules across a cell’s membrane. These two procedures help a cell to survive because they help maintain homestasis. (Diffusion) Homestasis is the steady or balanced state of a cell. (Diffusion) Therefore it is important to find what conditions will make these procedures occur to their greatest abilities. There are many variables in nature including temperature, concentration levels, volume and time. In the following report 2 temperatures we examined along with 2 different concentration levels. There includes a hot, 60 degrees, and cold, 5 degrees, temperature and an undiluted and diluted solution for both. The two constant variables in this experiment were the volume, 250 mL of water, and the time, 40 minutes, checking every 10 minutes. This experiment was performed to determine the optimal conditions for when osmosis and diffusion occur. Hypothesis:
Part A: The potassium permanganate will diffusion more evenly in hot water compared to the cold water because water molecules move faster when they are hotter. Part B: The “sausage” with the greatest change because of osmosis will be tube C which is undiluted corn syrup in a hot water bath. The reason for this is because the concentration gradient between the substance in the “sausage” and the water is the greatest and molecules move faster when the temperature is hotter. Materials:
Distilled water - cold (5 degrees)
- hot (60 degrees)
crushed ice30mL diluted corn syrup
2x Petri dish30mL undiluted corn syrup
100mL graduated cylinderhot plate
Potassium permanganateglass funnels
4x 15 cm dialysis tubing2x 250mL beakers
1. Hot water and cold water were placed in separate Petri dishes and then placed on a blank piece of paper. 2. 2 drops of potassium permanganate were placed in the center of eat Petri dish 3. During the following 30 minutes the dishes were observed periodically. Observations and changes were jotted down.
1. In order for the dialysis tubes to be opened they were bathed and massaged. 2. The closed end was tied with a string to make sure it would stay closed. 3. Two dialysis tubes were filled with the diluted corn syrup solution. Any air bubbles were removed and the other end was tied with a string. Both “sausages” were roughly the same length. 4. Step 3 was repeated with the undiluted corn syrup.
5. 50ml of water was placed into a graduated cylinder, then the volume of the sausages were recorded using water displacement. 6. The initial appearance of each sausage was described and recorded in the observation chart. 7. Two 250mL were filled with 250mL of water to form the hot and cold water baths. Sausage A and C were placed in a hot water bath and B and D were placed in a cold water bath. 8. The hot water beaker was placed on a hot plate to maintain the temperature of 60 degrees. The cold water beaker was placed in an ice water bath to maintain the temperature of 5 degrees. 9. Each sausage was observed every 10 minutes after the starting. They were also measured for volume and firmness which was then recorded on the observation chart.
Part A – drawings
Part B – observation chart
Time (mins)| A- Dilute Hot| B- Dilute Cold| C- Undiluted Hot | D- Undiluted Cold| 0 min| Volume- 12mLDescription- very soft, when pushing against the sausage can press fingers together-light yellowish colour| Volume- 12mLDescription- very soft, when pushing against the sausage can press fingers together-light yellowish colour| Volume-...