• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Osmosis, I predict the mass of potato will first increase then start decreasing as the concentration of salt increases. I think this because at first water will enter the potato

Extracts from this document...


OSMOSIS COURSEWORK OSMOSIS Aim: To investigate the effect of different concentrations of salt solutions on the mass of potato tissue. Background Information: Osmosis Some membranes allow some particles to pass through them and not others, they are partially permeable. Osmosis is a special type of diffusion - diffusion of water molecules through a partially permeable membrane. More water molecules pass from the water into the dilute solution than pass back the other way, because there is a higher concentration of water molecules in the pure water than there is in the solution. Eventually the level on the more concentrated side of the membrane will rise, while that on the less concentrated side falls. When the concentration of water is the same on both sides of the membrane, the movement of water will be the same in both directions. Osmosis in plants Plant cells have a strong cell wall surrounding them. When they take up water by osmosis they start to swell, but the cell wall prevents them from bursting. Plant cells become "turgid" when they are put in dilute solutions. Turgidity is very important to plants because this is what makes stand up into the sunlight. When plant cells are placed in concentrated sugar solutions they lose water by osmosis and they become "flaccid. ...read more.


I am happy with my results in the preliminary test. The preliminary test helped me inform my plan by giving me an idea how the experiment will be like and give expected results. Results: Test 1 Concentration of salt solution M 0 0.2 0.4 0.6 0.8 1.0 Mass before of potato cylinders (g) 0.99 1.02 0.98 1.01 1.01 1.01 Mass after of potato cylinders (g) 1.01 0.81 0.71 0.67 0.65 0.64 Change in mass of potato cylinders (g) +0.02 -0.21 -0.27 -0.34 -0.36 -0.37 Test 2 Concentration of salt solution M 0 0.2 0.4 0.6 0.8 1.0 Mass before of potato cylinders (g) 0.98 0.96 1.00 0.98 1.03 0.97 Mass after of potato cylinders (g) 1.05 0.85 0.76 0.66 0.62 0.61 Change in mass of potato cylinders (g) +0.07 -0.11 -0.24 -0.32 -0.41 -0.36 Test 3 Concentration of salt solution M 0 0.2 0.4 0.6 0.8 1.0 Mass before of potato cylinders (g) 1.04 0.93 1.05 0.99 0.99 0.98 Mass after of potato cylinders (g) 1.06 0.82 0.77 0.66 0.62 0.64 Change in mass of potato cylinders (g) +0.02 -0.11 -0.28 -0.33 -0.37 -0.34 Average results: Concentration of salt solution M Average mass before of potato cylinders (g) Average change in mass of potato cylinders (g) Average percentage change of mass (%) ...read more.


This would be because it increases in mass from the last point that was at a lower concentration. I think my results are still valid because I believe that it is a very small fluctuation in the graph. To increase accuracy I could do the experiment few more times and find the average of the results also I rounded my values up which would make my results less accurate. I can see from looking back to my method that some of my equipment could be improved to increase accuracy. For example I could have used burettes as they are a very accurate way to measure. Also I could use more accurate scales to measure the weight of the potato cylinders. The reliability of evidence for my work is very valid and I believe it is sufficient to support my conclusion. The preliminary test was very strange that its results where very different from all my other results. I think it could be to do with the potato or the equipment, as we did the preliminary test and the other tests on different days using different equipment. If I could take this investigation further, it would be to investigate active transport in plants. Active transport is the process by which dissolved molecules move across a cell membrane from a lower to a higher concentration. In active transport, it requires an input of energy from the cell. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our GCSE Green Plants as Organisms section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related GCSE Green Plants as Organisms essays

  1. Peer reviewed

    Osmosis in potato and apple

    3 star(s)

    Also, in the preliminary I used 1 chip of each plant tissue for each concentration, so I had all together 4 results for each plant tissue. If I was to have the same amount of result for my experiment, the conclusion I would come to would not be reliable.

  2. Determine the water potential of potato tuber cell with the varying affect of solute ...

    For change in mass you simple divide the change in mass by the original mass. For the percentage mass, you simply plot this against the molarity of the sucrose solutions. The Y axis will have at the top the increases in mass, no change in mass in the middle and

  1. The effect that different concentrations of salt solution in the water has on strips ...

    Each group varied different factors/aspects of their experiments from the size borer, to the different concentrations. The next step was for each group to perform the experiment, each group in a different way. My group (Me (Steffan), Rhys, Hazel, Holly, Daniel.

  2. Free essay

    Investigation osmosis in potato cells

    keep the chips in the mixture for eight minutes instead of five minutes to get more accurate readings and to let osmosis to occur longer.

  1. Test on osmosis and its effect on pieces of potato

    The cell will stay the same size. * If the liquid has a lower concentration of water than the cell (a very concentrated solution-hypertonic) the cell will lose water by osmosis. Again, water crosses the cell membrane in both directions, but this time more water leaves the cell than enters it.

  2. osmosis. I will be investigating the effects of different concentration of sugar solution will ...

    After setting up beakers and test tubes, I will place the potato chips inside the test-tubes I am pouring the different concentrations of sugar solution into each of its own test tube. After, I have poured the different concentrations of sugar solution into each of its own test tube, take

  1. Monitoring living organismsthe more concentration of salt there is, the less growth of the ...

    I would keep on doing this for 2 weeks, so I would know what is happening for the duration of the seeds growth. Monitoring would take place 11.00am and 23.00pm. Every time that I would note down the results, I would write down whether there has been any growth from

  2. Osmosis investigation. My prediction is that as the concentration of the solute increases, ...

    I could have chosen to use temperature as a variable, however I felt it would be wiser to chose otherwise, because if I used a tube in a water bath it would take too long to perform the experiment, as it would take too long for the tube to heat

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work