Investigate into the effect of varying concentrations of a sucrose solution on the mass of potato tissue contained in a potato chip.

Hypothesis:  My hypothesis is that as the concentration of the solution increases, the mass of the potato chips will decrease. This hypothesis is based on my prior knowledge of a process called Osmosis. Osmosis is the flow of water from a more dilute solution to a more concentrated solution through a selectively permeable membrane, in this case the potato cell membrane. Water is allowed to pass through the membrane in both directions and continues until the two concentrations are in a state of equilibrium, or equal. When a cell is holding as much water as possible it is said to fully turgid.

Method:  1. Set up Test tubes, five for each molarity level, making sure they are labelled.
2. Prepare the potato samples, cut out tubes using the same cork borer and then cut them to 2cm long using a scalpel. Making sure you clean your equipment to prevent contamination.
3. Immediately weigh each sample, and then place in the bathing solution.
4. Leave for 24 hours.
5. Remove samples; wipe off excess water on dry tissue paper.
6. Immediately re-weigh the samples and record the results.

Conclusion:  The results I collated from the experiment were consistently satisfactory and reliable. The graph clearly shows that the results support my original hypothesis that as the concentration of the solution increases, the mass of the potato chips will decrease. The only result that showed any signs of being inaccurate was the 0.6M solution, as this was slightly below the predicted level, this can be seen on the graph above. The probable cause of this slight change in consistency was that the measuring cylinder used to measure the solution at the start was not washed out thoroughly and so contaminated the following solution. I can use the above graph also to calculate the point of equilibrium of the solution and the potato tissue. As identified on the graph this point is 0.24M. This means that the concentration of both the solution and the potato tissue are equal.

Evaluation:  Overall I was satisfied with the way the experiment was carried out although there are a few things that, if I were to repeat this investigation, I would most likely do differently. Firstly I would ensure that the measuring cylinder was washed thoroughly each time to avoid contamination, which slightly affected my current results. Secondly I would leave the potato chips in the solution for a longer period of time which would produce much more accurate results.