• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month
Page
  1. 1
    1
  2. 2
    2
  3. 3
    3
  4. 4
    4
  5. 5
    5
  6. 6
    6
  7. 7
    7
  8. 8
    8
  9. 9
    9
  10. 10
    10

Factors affecting Osmosis in Potato Tissue.

Extracts from this document...

Introduction

Vicky Scurr 19/5/02 Factors affecting Osmosis in Potato Tissue Background Scientific Information: Key Variables: There are several variables we must consider. These are: 1. Length of potato chip 2. Mass of potato chips 3. Temperature 4. Variety of potato 5. Volume of salt solution 6. Duration 1. We must keep the length of potato chip the same because if some are longer than others then they have a larger surface area which will affect the rate of osmosis. 2. We have to weigh the potato chips at the beginning of the experiment and at the end so that we can measure the increase or decrease in mass. 3. The temperature must be kept the same as an increase in temperature may increase the rate of osmosis. 4. The variety of the potato is kept the same because 5. We keep the volume of the salt solution the same because if there is less salt solution in some of them then 6. We keep the duration of each experiment the same to make sure the experiment is a fair test which is why we keep all the others the same as well. To make this experiment a fair test we can only change one thing. This is the concentration of the salt solution. This is the independent variable. Hypothesis: I predict that if we double the concentration of the hydrochloric acid then the reaction rate will double. We are going to use a range of 3 to 1 molar so we have two doubles which are 1 and 2 and 1.5 and 3. The results will be directly proportional. ...read more.

Middle

The concentration of the hydrochloric acid is the only thing that we change. 2. Temperature stays the same. 3. The volume of the acid stays the same. 4. The length and width and depth will all be the same, because we can measure the length and the width and depth will be the same because all our magnesium will be taken from the same roll of magnesium ribbon. 5. There will be no catalyst present. 6. We will have straight magnesium ribbon. Observations: We have drawn up the tables of the results we got from the experiments. We have also done graphs. The tables show the time against the volume of hydrogen, and the graphs show the same thing, with a best fit curve. We can see that when the curve on the graph goes up, the volume of the hydrogen is increasing, but the rate of reaction is decreasing. Results: Results table 1 (3 molar) Time (s) Volume of hydrogen (cm )1 2 3 average 2 50 59 48 52.4 4 71 84 66 73.7 6 85 92 99 89.7 8 88 95 97 93.4 10 91 95 98 94.7 12 91 95 98 94.7 Results table 2 (2.5 molar) Time (s) Volume of hydrogen (cm ) 1 2 3 average 3 37 53 46 45.4 6 79 84 79 80.7 9 95 91 90 92 12 100 94 95 95.8 15 100 95 95 96.4 18 100 95 95 96.4 Results table 3 (2 molar) Time (s) Volume of Hydrogen (cm ) 1 2 3 average 3 18 18 28 21.4 6 27 40 45 37.4 9 53 53 70 58.7 12 67 66 84 72.4 15 77 77 88 80.7 18 83 82 89 84.7 21 84 82 89 85.0 24 84 82 89 85.0 Results table 4 (1.5 molar) ...read more.

Conclusion

There are also two anomalies on the graph on which I plotted rate of reaction against concentration, at 1.5 molar and 2.5 molar on the x axis. These are dues to some sort of experimental error. Another reason is that possibly the concentration of the hydrochloric acid was slightly different each of the three times we repeated each experiment. With the highest concentrations of hydrochloric acid, the reaction was over very fast, and the initial rate, which is what we are most interested in, was so fast that it was hard to measure the volume of hydrogen collected at exactly regular intervals. We might have been a fraction of a second out and that would have made a lot of difference to each individual result. I think that it altogether the procedure used to carry out the investigation is quite accurate and suitable. There are thing which could have been done to improve it. There are many limitations to this experiment because it is difficult to be exact with such limited apparatus. It is difficult to put the magnesium into the hydrochloric acid at the same time as putting the bung in and starting the stop clock. This means that some of the magnesium may already have reacted with the hydrochloric acid before it was possible to put the bung into the side armed flask. To find out more relevant information, we could have used a wider range of concentrations as then we could have seen more proof of our prediction being partially correct. I think that altogether the results are quite good and accurate because I have so few anomalies, and this is proof that it is quite accurate, because we can see where the inaccuracies are (where there are anomalies) and there aren't many. ...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 Patterns of Behaviour 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 Patterns of Behaviour essays

  1. Experiment to investigate factors affecting the rate of reaction between magnesium ribbon and hydrochloric ...

    This means that particles in higher concentrations will collide with magnesium particles more frequently, therefore increasing rate of reaction i.e. a shorter time measured for the magnesium to be used up in reaction. I can predict that rate of reaction will increase with concentration of acid.

  2. Factors Affecting Enzyme Activity

    0.0 30.0 32.0 32.0 32.0 32.0 32.0 32.0 Amount of gas given off using 1cm3 of liver suspension and 5cm3 of hydrogen peroxide(cm3) 0.0 18.0 26.0 34.0 36.0 36.0 36.0 36.0 Amount of gas given off using 0.5cm3 of liver suspension and 5cm3 of hydrogen peroxide(cm3)

  1. Experiment to investigate factors affecting the rate of reaction between magnesium ribbon and hydrochloric ...

    - I will conduct a preliminary experiment to investigate the optimum length of magnesium ribbon to be used in my experiments. 3cm, 2cm and 1cm of magnesium ribbon was dropped into separate beakers of 4cm3 of 2M hydrochloric acid. The time taken for the reaction to take place was measured with a stop-clock and recorded in the table below.

  2. Investigating factors that affect the rate of catalyse activity on potato tissue.

    The rate of reaction increases. It also lowers the activation energy. Activation Energy: All reactions need energy to start them off, even the exothermic ones. This is called the activation energy. It is the minimum energy required to get a reaction started. How do enzymes work?

  1. Potato and Osmosis Investigation

    substrate cannot fit the active site and just bounces of, so the particles don't react. Also if the temperature is too low the particles can slow down and not collide with each other that often meaning that there is a slower rate of reaction.

  2. An Investigation into the factors affecting the rate of reaction between magnesium and hydrochloric ...

    Investigation Experiment I am going to investigate how temperature affects the rate of reaction between magnesium and hydrochloric acid. The procedure for the experiment is as follows; * Using a measuring cylinder, measure 10cm3 of water and pour it into the side arm tube.

  1. Rate of reaction of hydrochloric acid and mangesium ribbon.

    The initial rate of reaction increase as the concentration of the acid increases 2. There is a fourfold increase in the rate of reaction as the concentration increases 3. As the concentration doubles the initial rate of reaction is approximately squared My original prediction was that the initial rate of reaction would double as the concentration doubles.

  2. An Investigation into the factors affecting the rate of reaction between magnesium and hydrochloric ...

    Analysing Evidence First three graphs were drawn (one for each time the whole experiment was carried out). So that the graphs did not become over crowded the curves were drawn on separate pieces of see through OHP film and overlaid each graph.

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