Plan: Firstly collect all the equipment in the apparatus list. Put the test tubes into the test tube racks and measure that the potato chips are cut to the same length and width. Then weigh the chips on the weigh scale to see if the chips are roughly the same weight.
Then measure 15cm³ of sucrose solution at 0.0M and pour it into one of the test tubes and label it according to the concentration so you know which one it is, continue this process until 1.0M. After doing this put it one potato chip into each of the test tubes and leave them for 15 minutes, I will time this using a stopwatch. After 15 minutes I will measure and weigh each chip to see if the chip has reacted with the sucrose solution, whether it has expanded, shrunk or stayed the same. I will record all my results in the results table. I will do each concentration three times to give me accurate results.
Fair test: To make this a fair test I will make sure that the chips are the same length and width. If I didn’t make sure the chips were the same I could end up with inaccurate results. I will also need to make sure that I have the same amount of solution each time because it could affect the results in the experiment.
Prediction: For 1.0M I predict that the chip will weigh less because the water particles in the chip were it is high concentration will diffuses into the solution were it is a lower concentration so the chip shrink. For 0.0M I predict that the chip will swell up because the water particles in the solution will diffuse into the chip because it goes from a high concentration (the solution) to a low concentration (the chip), causing the chip to swell up.
Results:
Analysis: From my graph I can see that as the concentration increases the weight of the chip stars to decrease. The chips in water grow by an average of 0.48g.As the concentration starts to increase the weight of the chip starts to decrease, because the water particles in the chip were it is high concentration will diffuse into the solution were it is a lower concentration. As the sucrose increases the chip still grows but not as much. As the concentration increases the chip stays the same at a certain point this is because the concentration and water inside and outside the chip are the same, this is known as equilibrium and this happens at approximately 0.5M. As the concentration keeps increasing the chips start to loose weight. I can see that at 0.0Mthe chip is at 0.48g but then slowly it starts to decrease because at 0.4M the chip is at 0.16g. Then at 1.0M the chip is at -0.48g. So I can see that as concentration increases the weight decreases. From my results you can see that my prediction was correct. I can see this from my graph and from my results table.
Evaluation: My results are reliable because they are close to the line of best fit and they follow a trend which is a negative correlation. My results are reliable and I can see this from the 0.6M concentration I can see that the differences in mass are all close to each other, +0.19, +0.20 and +0.21.The 0.0M is the anomalous result. This could have been caused by some small differences: the chips may not have been exactly the same length, width and weight. This may have been because the chip machine is cross section and the chips weren’t the same. Also the chips were a bit hard to handle because they were bendy and they were hard to cut exactly the same. Another reason could have been because it was difficult to measure the exact volume each time and it was difficult to see clearly the exact number. We could improve these problems by: using better chip cutting machines so that length, width and weight of the chip are all the same. We could use better measuring cylinders which are thinner and more accurate to see. Also we should make our own concentrations because the other concentrations could have become contaminated. We also were not able to put the chips in at the same time and we were not able to put them in at the same time, having more people to help could have improved this problem. All the chips were not dried evenly we could have dabbed on each side a equal amount of time applying the same amount of pressure each time. Another problem I came across was that we had to wait for the scales a long time and this made the chips dry out as we were waiting. For this problem it could have been solved if each group had their own pair of scales.
The chips were not the same weight to start of with so the change in weight was not the best way of looking at the results, its not a very fair test Another problem I came across was that we had to wait for the scales a long time and this made the chips dry out as we were waiting. For this problem it could have been solved if each group had their own pair of scales.
The chips were not the same weight to start of with so the change in weight was not the best way of looking at the results; it’s not a very fair test. A better way is too look at percentage change in weight. If I was to do the experiment again I would change the temperature of the water and this is another variable. I would have to change the temperature of the sucrose solution from low temperature and gradually get to a higher temperature then add the potato chips to each concentration. I could use a kettle to boil the water to the different temperatures. After adding the chips to the boiling tubes and leaving them in the solution for the same amount of time e.g. 15minutes, you can take the chips out of the boiling tubes and see which chips have increased, decreased or stayed the same.
