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How is osmosis affected by different concentrations of solute?

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Investigating Osmosis How is osmosis affected by different concentrations of solute? Introduction What is osmosis? Osmosis is where water travels across a semi - permeable membrane from where there is more concentrated water to where it is less concentrated. This allows the water molecules through but not the larger solute molecules. The water passes both ways through the membrane but the net flow is to the region with a lower concentration of water. The levels of water will be different. One will be higher than the other. Osmosis and diffusion are different. Osmosis a process that is the movement of only water across a semi - permeable membrane where as diffusion is the movement of particles from a higher concentration to a lower concentration. Both osmosis and diffusion are examples of active transport - substances are moving down a concentration gradient. No energy is needed for this process to happen. This happens inside cells. The cytoplasm of the cells contains sugars, salts and proteins and has a lower concentration of water than the outside of the cell. As more water enters the cell the cytoplasm presses outwards, in plant cells the cell wall will stretch allowing the water to support the plant inside. Animal cells have no cell wall and will explode eventually if they continually take in water. Hypertonic solutions: This solution contains a high concentration of solute relative to another solution, e.g. ...read more.


25 � 50 = 0.4. I also tried this with other points on my graph to make sure they were the same - and they were. The gradient of my graph is 0.4. Anomalous results I found that I had many outliers. They were in the % change of mass column. They were mainly in the second test, I found 2 outliers in the second test one for 50% concentration of sugar solution and another for 75% concentration of sugar solution and 1 in the first test for 0% concentration of sugar solution and one for the last test I did for 100% concentration of sugar solution. I identified them when I put the results into my table. This is where I realised that some of the results were too high or too low as there were only minor differences between the other two results. For example, for the first test I found an outlier in the % change column which was 30%, it was for 0% concentration of sugar solution. This is an outlier because the other two results for the same concentration were 14% and 15%. So this result was too high to be accurate. Another example is where one of the outliers was too low to be accurate. The other results were -25 and -26 and the outlier was -19. I also had an outlier that was -37 and the other results were -9 and -2. ...read more.


I had a few problems sometimes the cork borer didn't work so I didn't always have the same potato sizes and sometimes there were times when the balance did not work. The objective of this experiment is to show the process of osmosis. I got the results that I vaguely expected but I didn't expect to get a lot of outliers. I expected to find maybe one but not as many as I did get. I used 1 piece of potato in 5 concentrations and repeated the test. I reviewed my method I think that if I were to do the experiment again it would be better to have consistency. I don't think there was much consistency in my method apart from using the same balance. I think it would have been better to do all three repeats at the same time on the same day. It would have been accurate. I could use the readings from all of them and it would have been more accurate. I also need to make sure that I dried all of the potato pieces with the same pressure, and in the same way. for example, if I decide to roll each potato piece to and from the same points each time and with the same pressure it would be consistent and It may affect the results, I might not have as many outliers as I did. This graph shows the mass at the start and at the end of test 3. The graph also shows a point where the lines overlap. ?? ?? ?? ?? 1 ...read more.

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