Method
- Cut the potatoes into slices 1cm long using a knife.
- Label test tubes and fill with ONE sugar solution.
- Dry the potato slices then Weigh them and record them on a table.
- Insert the potatoes into the test tubes and use stop watch to record time.
- Wait 15 minutes then remove the potatoes and dry them. Then record their new weights
- Repeat with different solutions
Preliminary Work
Before starting the test I have done some preliminary work. I did this so I was able to get an idea of how the results should look when doing the test for real. This way I stop false results from altering my final conclusion to the test.
Before Sugar 10.96g
After Sugar 10.56g
Before Water 11.32g
After Water 11.45g
This shows that the water does move from a high concentration to a low concentration.
Prediction
I predict that on 30 percent of sugar solution the weight of the potatoes will decrease but on the other solutions they will increase or remain the same.
I believe this because this solution has the highest sugar concentration. Therefore osmosis will have to transfer the water from the low sugar solution in the cell to the high sugar solution where there is less water. Otherwise the situation would be unbalanced stopping the process from continuing causing cells to die along with life.
I also predict that in the 5 and 10 % sugar solutions the mass of the potato would increase as the potato will have a higher solution of sugar than 5% or 10% therefore meaning the process in the 30% would be in reverse. So the water from the solution would transfer in the cell with the lower level of water but the higher sugar level.
Planning to collect good data
Our group made the investigation fair because we used 5 potatoes on each concentration meaning we would have many results giving us a better average and a better result. We repeated the whole test using all the concentrations twice as this gave us two averages making sure our original was not corrupt. The concentrations we used were 5% sugar 10%, 15%, 20% and 30%.
In order to keep the test fair and accurate we used the same size potatoes and using a stopwatch to keep the emersion time constant in all the tests. The accuracy of the equipment was down to the condition of the scales and stopwatch when they were under our use.
Results shown in grams
Conclusion
The results table is showing me that the lowest concentration of sugar water (5 and 10%) had the most increase in mass in the potato chip, it also shows that the 30% sugar solution had the most results showing lost mass after being left in the sugar solution. The trend I’m seeing is that the lowest sugar solution showed the greatest mass improvement but the 10% for some reason showed some lost mass in two of the potato slices, even though the lost was a very small amount. This conclusion could be used to benefit medical science by explaining to us that if the right amount of sugar is in someone blood then the cells will over absorb or release too much water making their cells shrivel or burst depending on the level of sugar added to the person’s cells. We could also learn about why our bodies have diabetes and possibly learn to use reverse osmosis in our favour, for example using it to remove too much sugar from someone who has eaten too much and is becoming too dehydrated because of it or to save someone’s life that has overdosed on drugs and need to remove dilute the drug in the cells in their body.
Evaluation
I feel that these results may not have been the most accurate; I predicted that the 30% solution would have been the more effective at increasing the weight of the potato slices and I still believe it would do so after this test. My theory was that because the sugar in the solution was higher than the potatoes cells the water from the potato cells would transfer through the cells membrane and into the solution because of its lower concentration of water. Anomalous results may have occurred because of defective cells in the potato, for example cells that have already died cannot transfer water, as they are immobile.
As I said earlier I don’t think my result were terribly accurate so in order to back up my prediction I could re-do the test, but this time take two sets of results in case the first or second result are incorrect which could have been the possibility with this test. As I’m not sure if I do have enough correct data I cannot yet give a certain conclusion and anything said could be incorrect. I don’t believe that the equipment used, apart from the potato and the solution, could have changed the final results because they have no real purpose, apart from containing, timing and weighing which they all seemed good at doing. The method used I feel was fine, I could have used a better environment though, one that didn’t involve me moving too much to reach the electronic scales or the test tubes etc.