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

To find the effect of concentration on osmosis

Extracts from this document...


Investigation to find the effect of concentration on the effect of osmosis Aim: To find the effect of concentration on osmosis Preliminary Work: Osmosis is a specific type of diffusion. It occurs when a membrane has tiny holes in it that let water molecules pass through, but stops larger molecules like sugar. A membrane that allows only the small molecules through is called a semi permeable membrane. Therefor an impermeable membrane allows no molecules through and a permeable membrane allows all molecules through. Osmosis is where water molecules diffuse or move from an area of high water concentration to an area of low water concentration. Put simply osmosis is the diffusion of water. Diagram 1: An example of osmosis showing the movement of water molecules between adjacent cells: This diagram above shows how when the concentration of water molecules is higher than in the cell next to it they diffuse through the cell membrane. Osmosis occurs in plant and animal cells. The cell membrane of the cells is semi permeable. So if a cell containing a strong concentration of water is next to a cell with a low concentration of water, water molecules pass from the high concentration to the low concentration. In a plant cell water moves from cell to cell by osmosis. This evens out the water in a plant and helps transport water around the cells. The maximum amount of water able to be taken in by a plant cell is controlled by the cell wall, which stops the expansion of the cell and so stops it from bursting. ...read more.


The overall volumes will need to be the same to make the test a fair one so I have decided that the volumes will all add up to 30 cm�. The volumes of each test tube are shown below: 30cm� salt solution + 0cm� distilled water 25cm� salt solution + 5cm� distilled water 20cm� salt solution + 10cm� distilled water 15cm� salt solution + 15cm� distilled water 10cm� salt solution + 20cm� distilled water 5cm� salt solution + 25cm� distilled water 0cm� salt solution + 30cm� distilled water These 7 concentrations will provide me with a large enough range to produce reliable results. The test tubes will have the concentrations marked on them to prevent any mix-ups, which could lead to, inaccurate or no results for some of the concentrations. The test tubes will then have a piece of potato carefully placed within. This potato will be 3.00g in mass. In order to make the experiment fair the potatoes placed in the test tubes will all need to have the same weight and surface area. To do this they will be cut using a corer, this will ensure that they all are cylinders with the same diameter and circumference. They will then be cut into pieces 3.00g in weight using a scalpel. To make sure that they are the same weight they will all be dried carefully using a paper towel. ...read more.


Conclusion: I conclude that the rate of osmosis is affected by concentration. This is because of the evidence that I have found in my experiment and gathered in my research. Evaluation: I believe that the experiment I carried out went well. This is because my prediction was proved correct by my results. I believe my results to be an accurate representation of the effect of concentration on osmosis. This is because it agrees with my knowledge and research and also as I produced no anomalous results in collecting them. If I had it would be difficult to prevent due to the environment and limited resources available. However if I did produce any as stated in my method I would redo that section of tests from the beginning. To improve the experiment I would have liked to control new factors that affect osmosis. For example temperature, this would mean that I would be able to prevent some factors, which could cause anomalous results. Also I could refine the method to allow more tests and a wider range of results to back up my findings, this would help make my results more reliable There could also be more experiments carried out by different people who could then combine their result with mine to check them, as there are not the facilities at school to keep the temperature at a constant one for all experiments. I will make sure that the salt solution comes from the same batch. This is so that the concentration is the same before distilled water is added. Craig Banfield Page 1 of 3 ...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. Determine the water potential of potato tuber cell with the varying affect of solute ...

    My preliminary work helped me to predict this. Potato tuber cell (cylinder) Many water particles entering cell Some water leaving cell My next prediction was for the 0.2 mol dm-3 sucrose solution. For this prediction I predicted that again there will be a gain in mass but this time less then before.

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

    to be used, 2 test tubes for each concentration labelled A and B (1 Strip of potato for each test tube, then average percentage change worked out for each concentration). The factors I shall be varying are: Concentration (salt solution)

  1. What effect does the sucrose concentration have on osmosis?

    % Sucrose % Water Volume (cm3) Initial Mass (g) Final Mass (g) Change in Mass (g) Average Change in Mass(g) % Difference Average % Difference 1 50.00% 50.00% 20 1.94 1.58 -0.36 -18.00% 2 50.00% 50.00% 20 1.87 1.49 -0.38 -20.00% 3 50.00% 50.00% 20 1.90 1.56 -0.34 -0.36 -18.00% -18.67% Exp.

  2. The factors affecting the rate of permeability in a cell membrane?

    Safety: In order to carry out the experiment safely and precisely the following safety procedures must be performed. * Wear goggles * Wear protective overcoat * Tie back long hair * Do not eat in the laboratory * Put all coats and bags out of the way * Put all

  1. Potato and Osmosis Investigation.

    MAIN INVESTIGATION: Aim: To investigate the effect of varying concentration of a sugar solution on the amount of osmotic activity between the solution and a potato chip at a given size. Hypothesis: Osmosis is defined as the net movement of water molecules from a region of high concentration to a

  2. Water moves from a high concentration gradient of water to a low concentration of ...

    cm� 1 molar diluted sucrose solution * 3x Boiling Tubes * Beaker * Potato * Knife * Tile * 10 cm� Measuring Cylinder * Sticky Label * Cork borer Diagram Test Tube Tube Rack Potato Different concentrations Method 1. Firstly put on your safety goggles ensuring that you will not infect your eyes.

  1. Investigate the cell sap concentration of solute in a potato chip using osmosis and ...

    planning can be realised and rectified, the investigators can get used to the equipment and make changes without impacting on the actual results of the experiment that will be analysed, problems with the equipment can be seen, the range of results can be decided on after analysing the results of

  2. An investigation into the effect of differing water potentials on the mass or volume ...

    Unlike animal cells they don't burst, this is due to the strong cell wall, which can withstand high pressures. This feature is useful for guard cells of the stomata in leaves so that water or vital substances aren't lost through the stomata on the underside of the leaf.

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