Prediction: I predict that when a chip is placed in the pure water and left, water will enter it by osmosis this making it way more on its removal. But when a chip is placed in a sugar solution and left, on its removal it will weigh less. The more sugar used in each sugar solution, the lighter the chip will be when it is removed.
Hypothesis: I think that what I have said it my prediction is what will happen during the experiment because the pure water will allow the chip to absorb it by osmosis whereas the sugar solutions will leave the chip by osmosis main the chip lighter. I learnt about this while studying ‘The Essentials AQA Science Double Award Modular-The Tested Modules Page 25. This book told me a definition or the word osmosis and a similar experiment to do with osmosis.
Apparatus:
- 12 Test tubes- To put the cut potatoes and solutions in
- Cutting Tile-To cut the potatoes on
- Scalpel Knife- To cut the potatoes to the correct length (6cm)
- Measuring Cylinder-To measure the solutions
- Pure Water-Part of the experiment
- Caster Sugar-Part of the experiment
- Paper Towels-To dry the potatoes after osmosis has taken place
- Electronic Weighing Scales- To weigh the sugar and potatoes
- Potato Slice-To cut potatoes into chips
- Potatoes- Part of the experiment
- Pen-To write with
- 12 Sticky Labels- To label the test tubes 1-6
Diagram of Apparatus:
Method: First I got the apparatus listed above. I cut 1 potato in to chips using the chip slice. I gathered 12 chips from the slice, and cut them all the same length (6cm) using the scalpel knife and the cutting tile. I lined 6 of the potatoes on a paper towel and numbered them 1-6 using the pen. I placed the other 6 on a different piece of paper towel and numbered them 1-6 using the pen. I then set the electronic measuring scales to the grams setting and measured each chip, I then recorded there weights on my results table. I then labelled 6 of the test tubes 1-6, and then repeated this with the other 6. I then measured 100ml pure water in a measuring cylinder and put 20ml it in each of the test tubes labelled number 1. I placed chip number 1 from each paper towel in test tube number 1 (1 in each). I then poured the rest of the water down the sink. I then set the electric measuring scales to the grams setting and measured 1g of sugar. I poured the sugar in the measuring cylinder and filled it up with 100ml of pure water. Next, I gave the solution a stir and poured 20ml of it in each of test tube number 2. I repeated this with 2g, 3g, 4g, and 5g of sugar. With each of the sugar solutions pour them into the same number test tube, for example 2g in test tubes numbered 2 etc. I left the solution for 48 hours. After 48 hours I took each potato out of the solution. I laid the 1st 6 potatoes on the paper towel in a row a numbered them 1-6. It is very important that you place chip number 1 on the paper towel number 1 and the same for the others. I repeated this with another paper towel and with the other chips. I dried each of the chips to get the remaining solution and water off them. I then set the electronic measuring scales to the grams setting a re-measured the chips, I then recorded the results on the results table.
Results Table:
Conclusion: I feel I collected enough evidence during the experiment to support my hypothesis.
The evidence I have gathered during the experiment is:
- Osmosis did take place in the experiment
- Pure water chip did way more on removal
- The greater sugar solution the less the chip weighed on removal
Evaluation: I feel the experiment went well overall; I followed the instructions given to me by Mr Sheridan. To make the experiment more successful I believe that we could have left the chips in the potatoes longer, to see if that changed the results. Also you could add more solution instead of 20ml, maybe 35ml for example. I could make a higher concentration of sugar solution to see if this affected the results. I could also decrease the amount of water used in the whole experiment and leave the experiment for a shorter period of time.