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

What variables effect omosis in potatoes

Extracts from this document...

Introduction

GCSE Coursework

What variables effect omosis in potatoes.

Information about osmosis.

Osmosis is the movement of water molecules from a region where there is high concentration to where there is low concentration, this often occurs across a selectively permeable membrane. This is an area of selectively permeable cells that only allow certain substances to cross and prohibit others. The reduction in size of the chip may be due to this process.

In a plant cell – if it is put into pure H2O, it will not rupture because the cell wall is fully permeable to water so therefore osmosis can not occur.

Osmosis in a cell membrane – cell membranes are selectively permeable and if put into pure water it would swell because the cell wall is strong. They also do not burst but becomes turgid.

If a plant cell is put into a salt solution, water moves out of the cell and so the cell shrinks and becomes flaccid. This process is called Plasmolysis, the plant cell shrinks because the cell membrane tears away form the cell wall.

Aim

To find out what difference the concentration of a salt solution makes to the size of a raw potato chip.

I predict that that there is a proportional relationship between the current flowing through the wire and the strength of an electromagnet. Therefore this means that as one is increased then the other will increase. I think this due to the domain theory.

...read more.

Middle

10. Remove all of the iron filings collected in the container and weigh on the digital scales.

11. Record the results in a pre-made chart.

12. Remove the core from the wire coil and bang on a hard surface to remove any retained magnetism then repeat the experiment for each level of ampere (Starting at 1amps and increasing the amperes by 0.2amps each time until 2.6amps is reached).

This is a blue print of the circuit that should be constructed in order to carry out the experiment:  

image00.png

Equipment

Below is a list of all of the equipment that is essential requirements to carry out the experiment:

1x        Iron nail (10cm in length)

Insulated copper wires (50 coils around the shaft of the nail)

1x        Power pack

8x        Connecting wires and crocodile clips (

1x        Voltmeter

1x        Ammeter

1x        Variable resistor

1x        Iron filings (150grams, enough to repeat the whole experiment three times)

1x        Digital scales (Measurement of 2 decimal place accuracy)

Fair Test

To ensure that my test is as fair and non-biased as possible, I am going to keep all of the variables the same, except for current, which of course needs to change as this is the factor that is being investigated.

Also, to ensure accurate results, when measuring the iron filings I am going to use digital scales that supply information to 2 decimal places which I feel is an appropriate accuracy for the results that need to be obtained.

...read more.

Conclusion

Evaluation

Overall, I feel that the methods that I used to gain the results were very accurate and fair, although if I wanted to improve the quality and the validity of the results I would possible conduct the experiment in a different way. I would allow myself an appropriate amount of time in which I would repeat the experiment to confirm any possible trends that may be found. By doing this any possible anomalous results would be eliminated and a more sound picture of the results could have been given. Although despite this I believe my investigation has been very successful. My original prediction was proven to be correct and I feel satisfied that the experiment enabled me to gather suitable data that allowed me to make a valid conclusion. I have studied the graph and it was possible for me to identify some anomalous results. The most obvious one was in the first experiment at 1.8amps on the graph rises sharply and does not fit the line of best fit. I feel that this suggests this result is inaccurate. The result for 1.8amps from the second experiment confirms that the result was anomalous. The line of best fit for the average results (obtained from the mean average of the two experiments) represents an expected trend. The line is almost flat. I think that the graph would have been a perfectly straight line if the experiment were conducted in absolutely, perfectly controlled conditions.  If I were to repeat my experiment I would increase the current until the saturation point of the core.

By Ross Smith 11G

...read more.

This student written piece of work is one of many that can be found in our AS and A Level Electrical & Thermal Physics 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 AS and A Level Electrical & Thermal Physics essays

  1. Investigating the effect of 'length' on the resistance of a wire

    * The crocodile clips may not have been placed on the exact point for the length required. The length could have been greater or less than the required length, giving a higher or lower resistance. * Analogue voltmeters and ammeters do not give a high degree of accuracy due to manmade reading errors.

  2. Investigating the Smoothing Effect of a Capacitor on a Resistive Load

    The most likely faulty method is measuring the voltage from the trace as it introduces the possibility of both systematic and random errors. The graph of the calculated ripple voltage against the ripple voltage shows a straight line through the origin, taking the form of y = mx , where m is the gradient of the line.

  1. resistivity if a nichrome wire

    So it had an absolute error of 0.01 as this was the ammeters accuracy. To calculated the percentage error for the current as follows: 0.01 x 100 = 4.17% (3 s.f) Therefore the percentage error for the current is 0.24 4.17 % 0.24 Voltage error Absolute: I first work out the voltage absolute error.

  2. physics sensor coursework

    The change in sensitivity is very rapid though. Before 100 lux, we experience a large change in resistance even with a small change in light intensity. After 300 lux though, any additional change in light intensity causes an extremely small change in the resistance. This can be measured as the gradient of the graph.

  1. Investigating the monitoring systems used on modern day large A/C for detection of specific ...

    A system contains essentially of a vibration pick - up unit mounted on the engine at right angles to the axis, an amplifier monitoring unit and a moving coil microammeter calibrated to show vibration amplitude in thousands of an inch.

  2. To investigate the effects of two different variables on a solar cell output.

    They'll simply pass through the cell as if it were transparent. Still other photons have too much energy. Only a certain amount of energy is required to knock an electron loose. This is called the band gap energy of a material.

  1. How does the mass of copper plated in the electrolysis of copper sulphate solution ...

    Furthermore, we are going to keep the depth of the solution the same because I want the same amount of copper ions in the solution and this also links in with the emersion of the electrodes in the copper sulphate solution so also the same depth is going to keep

  2. Investigate the effects of two different variables on a solar cell output.

    They'll simply pass through the cell as if it were transparent. Still other photons have too much energy. Only a certain amount of energy is required to knock an electron loose. This is called the band gap energy of a material.

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