I am going to do all the experiments at room temperature.
The mass of the potato is a dependent variable, and this means that it will be measured
I will be using the same type of potato, which have been treated in the same way, e.g. have all been cut without being washed and peeled.
The mass of the potato is a dependent variable, and this means that it will be measured throughout the experiment. I will measure the mass in grams. The potato chip will be measured before it is put in the solution, and after. This will allow us to see whether anything has happened..
The potato chips must be totally covered in the solution, and the amount of solution will be kept the same because all the potato chips are the same size.
Apparatus:
Potato chips
Six petri dishes
Labelling stickers
Electronic scales
Sucrose soloutions ranging from 0.00molar to 1.00 molar
Electronic stopwatch
Method:
First, I took six petri dishes, lined them up on the table, and put a sticker on the lid so I knew which one was which. Then I filled the petri dishes half full of each of the sugar and water soloution, and wrote their molar values on the stickers. I then weighed each of the potato chips, and then put them in each petri dish. I quickly put 2 potato chips into each petri dish, and and started the stop watch. After 30 minutes, I took out the potato chips, and lined them up with the petri dishes, so as not to confuse myself. I poured the soloutions out of the petri dishes, and weighed the potato chips again. I repeated this process twice, on different days, and averaged the results so I could get a more accurate view on the changes.
Results:
First attempt:
Second attempt:
These results give me an overall impression on the change in mass when placed in varying concentrations of sucrose solution
A graph to clarify the information in the table above
.
The gradient of the line on the graph above changes towards the end of the line, showing that the potato chips were near saturation point as I increased the concentration of sugar in the water.
Evaluation:
The experiment was very successful in my opinion. I obtained a large quantity of very accurate results from which I was able to create informative graphs. I think I took easily enough results for the amount of concentrations that I was using, and the time that I used for the experiment to last was enough to allow sufficient osmosis to occur. However if I was to repeat the experiment I might well increase the time of the result to allow more osmosis to happen and possibly find out the saturation point of the chips. The range of concentrations was adequate but I would possibly create more concentrations if I repeated the experiment so that I would have more varied results, i.e. 0.10m, 1.15m, 1.20m, and so on.
