Osmosis

Osmosis is the movement of a substance from a high concentration to a low concentration.

Diagram:

The Aim: The aim of the experiment was to find the molar concentration of a potato taken from an average of our results.

Method

1. Get the equipment on the equipment list.

2. Pick up the cutting tile and potato.

3. Cut the potato using the corer

4. Measure the core’s diameter and length.

5. Remove skin from potato core ends.

6. Cut the core down to a length of 40mm.

7. Measure the mass of the potato core using digital scales.

8. Record the mass in table.

9. Pour 30ml of distilled water into the boiling tube/ sucrose solution mixture to gain the correct concentration.

10. Set boiling tube in rack.

11. Insert the potato core into the boiling tube simultaneously starting the stopwatch.

12. Wait for 20 minutes.

13. Remove potato core shake off excess water on surface.

14. Measure the mass on the (0.00) accurate digital scales.

15. Record the mass in the table.

16. Repeat for each molar concentrations 3 times and record results.

Prediction and Preliminary work

Before I began the final experiment I conducted a preliminary one to uncover any problems we may encounter in the actual one. Furthermore the preliminary experiment will aid in making an accurate prediction based on the results as well as theory. In this experiment I used a sucrose solution of 0.0m and one of 1.0, these would be the two ends of the scale for my final experiment. By testing each end of the scale we can get a rough idea of the gradient of osmosis in and out of the potato in the solutions between 1.0m and 0.0m. The results will show at which molar levels there is a net movement out of the potato; into the potato and equilibrium is reached.

My prediction is based on my scientific knowledge and preliminary work.

Osmosis Coursework

Variables

During the experiment the variables must be controlled in that the results be fair and accurate.

· Time- 20 min. The time the potato remains in the solution must remain the same each time but must also be long enough for a significant change in the potato’s mass to have occurred.

· Surface area- Surface area affects the amount