Results of Preliminary Work
From my preliminary work I have learnt that it is better to use the potato chips in strong sugar solution as it shows a clear indication weather osmosis happened or not , By doing the preliminary work it has helped out a lot with my practical because it helped me identify and remove any possible mistakes before doing the real practical, as well as making sure I knew what I was doing and what equipment I had to use during the real practical.
Investigating Osmosis
The Practical
In the practical I worked with a partner ,we had 18 experiments to do 3 of each solution 0, 0.2, 0.4, 0.6 , 08 and 1 this ensures that we have a repetition of each experiment which makes it more reliable, the experiment was done with the time limit of 22 hours.
Equipment list
- 18 Small Beakers
- Cork Borer
- Plant Cell Potato
- Electric Scale
- Paper Tissue
- Sticky Labels
- Cling Film
- Sugar Concentration
Method
- I collected all the equipment as shown in the list.
- Measured out 10ml of all the solutions 0, 0.2,0.4,0.6,.0.8 and 1 and place into the beaker
- Use the cork borer to cut out 18 potato chips
- Measure mass
- Put potato and details of mass onto sticky labels and apply onto beakers
- Cover each beaker with cling film so that the solution does not evaporate
- Leave for 22 hours
- Then take out each chip and dry and measure mass
- Enter results into table.
Results
Average: 1.7
Average: 1.3
Average :1.36
Average:0.96
Average :0.8
Average :0.86
Conclusion
The percentage change in the results show that the chip has lost that amount of mass.
The results show you what happened when the potato chips where placed in high and low concentrations , it also shows a contrast.
The results show that the higher the concentration is the more flaccid the plant cell becomes this is because when the cells are put into the solution the water particles move accordingly. If the solution has less water particles than the cell sap in the vacuole [strong solution], then the water particles will move out, making the plant shrivel up.
Investigating Osmosis
Evaluation
The experiment that we carried out was successful in my opinion. I received a large amount of accurate which I was able to create and informative graph. I think that I took enough results for the amount of solution and the time for osmosis to happen , If I was to repeat the experiment I would increase the time to at least 24 hours so that osmosis would happen effectively also I would increase the concentration levels so I would have more varied results I.e. 0.3m ,0.5m and 0.7m , by doing this it would have allowed me to also find out the isotonic point more accurately as the one that I estimated is very approximate.
There weren’t any out of the ordinary results, there was one result which was not close to the line of best fit this may have been caused by me drying the chips too much when they were removed from the test tube, this could have led to some excess water which had remained in the potato chip add to the amount of mass, by being able to repeat the experiment I would find a way to dry the potato chips the same way this would help make my results more accurate.
The most difficult part of the experiment was cutting the potato although I was concentrating on the mass and length this might have effected the overall rate of osmosis. The use of a burette would have been helpful with this part of the experiment as it would have helped me measure small amounts of sugar solutions easily.
The results of my experiment is reliable as the repeats were close to each other. I have identified an outlier in my results when mass was measured at 0.4molars this could have been triggered by the lack of drying when it was taken out of the test tube or it could have been triggered by the size of the potato chip.When I repeated my results I found that most of them were close together either a few higher or lower which makes the results reliable but even though they are reliable there is no knowing weather its was carried out completely accurate.
The way the experiment was carried out is reliable as I used the same equipment through-out , I think that my conclusion should be believed as I received reliable and pretty accurate results the reliability of my data is reliable as it shows the results were close had only had one outlier.
