Method
Apparatus
Beakers -
Boiling tube -
Pipettes -
Chipper -
White Tile 10cm2
Scalpel -
Boiling Tube Rack -
- Set up equipment.
- Add 75% salt water to one beaker, 50% to another, 100% to another and 0% to another.
- Weigh the chip.
- Put the chip into the solution.
- Weigh again after some time.
- Neatly put away equipment.
I will take measurements of the weigh of the chips I add to the solutions. I will take the measurements thrice to make sure I have not weighed the chips incorrectly and that they are not a fluke. I shall keep the same amount of solution to make this a fair test, (30ml). My investigation will be safe because I will make sure I record the results neatly before throwing away my chips. They will not be touched by anyone else either.
Results
My results show me that the higher amount of sugar water in the boiling tube, the less the chip weighs at the end. All the results match this pattern. This is because the more sugar water there is, the less water will get to the chip due to the selectively permeable membrane and osmosis.
Conclusions
To conclude, my results showed me that the more pure water on the outside of the chip, the more water would go in so the chip weight gained. However, when you add the salt water, water comes out of the chip and the chip loses weight.
Discussion
I am sure my results are accurate as I measured the weight several times and took the average weight each time. However I think that the final weight I took would probably be the most accurate because the chip would have dried properly and I wouldn’t have worried about taking any of the skin off.
My results are extremely reliable because I did take averages and I think that my results are much more accurate then those of someone who only recorded the weight once.
My results match my prediction of the experiment. The chips have gained weight wen they have gained water and lost weight when they have lost water.
My results are as they are because the chi has a selectively permeable membrane. This means that only small molecules like water can pass through. The sugar molecules are too big so if the chip is surrounded with sugar water, it will not gain weight, as the molecules are too big to pass through the gaps in the membrane. However, if the chips were completely surrounded by water, the weight of the chip should theoretically increase because the water has small enough molecules to pass through the membrane.
You could do many more experiments to investigate the problem further such as; measuring the temperature and measuring the length of the chip. You would achieve this by putting some chips in a water bath, (first weighing them of course), then taking the different temperatures of the water baths. Leave the chips for a period of time and then come back and weigh them. Measuring the length of the chip would be easy. You would weigh the chips at their different lengths, add them to water, leave them for a period of time and then weigh them again at the end of it.
