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

I am investigating how the concentration of hydrogen peroxide affects the rate of a reaction.

Extracts from this document...


Effects on a named variable on rate of a catalase catalysed reaction I am investigating how the concentration of hydrogen peroxide affects the rate of a reaction. I can find this out by finding out how much gas is given off when I place a piece of potato in different concentrations of hydrogen peroxide. As I change the input variable (the concentration), I will measure the amount of gas that has been collected in three minutes. I am using a potato chip that is 2cm. in length, 1cm. wide and 1cm. deep and I am going to be adding this into hydrogen peroxide, which will be diluted with varied amounts of water. Enzymes are biological catalysts; they speed up chemical reactions in living things. Enzymes are specific, which is to say that they will only catalyse one particular reaction. One particular enzyme is catalase. This is the fastest enzyme, and is found in most living cells. The reaction that I will be using in my experiment is: Catalase Hydrogen peroxide � water + oxygen 2H2O2 2H20 02 This reaction occurs because catalase breaks down hydrogen peroxide producing small bubbles of oxygen. The reason that we are using potato is that it contains catalase, and this can be released when the potato is cut. ...read more.


* Potato chips Method: To investigate how the concentration of hydrogen peroxide affects the rate of reaction when using the enzyme, catalase, we took a piece of potato measured to the standard size and poured hydrogen peroxide, diluted and undiluted, into a boiling tube. We made a range of dilutions, they were as follows: Volume of hydrogen peroxide (cm�) Volume of water (cm�) Concentration H202 (%) 20 0 100 16 4 80 12 8 60 8 15 40 4 16 20 0 20 0 Each time, the amount of fluid (hydrogen peroxide + water) totalled 20cm�. * Once the correct amount had been placed into the boiling tube, the potato chip was added. * The bung was placed onto the boiling tube as soon as the potato chip came into contact with the hydrogen peroxide. * While the bung was being placed on the test tube the stopwatch was started. * After three minutes the stopwatch was stopped and we looked at the gas syringe to see how much gas has been released. * I then noted down the results. * I repeated the experiment another two times giving me three sets of results. This made my results fairer and more accurate. ...read more.


There could of also of been a slight change in the measurement of hydrogen peroxide or water used. My results show the pattern of a straight line but some points do not lie along it. My line of best fit passes through the point of origin, showing that the concentration is proportional to the rate of reaction. At the end of my line it may of tailed off to another point, that I have marked as anomalous, showing that the rate of reaction did not increase after a certain concentration. Most of my results seem to follow the pattern but there are a couple of anomalous results but the evidence quite strongly supports my prediction. If I were to do the experiment again I would make some alterations. I would test more concentrations with smaller intervals between each measurement. For example o would test 10, 30, 50, 70 and 90% as well to give me a wider range of results, which would also hopefully prevent me getting any anomalies. Another amendment that I could make could be a change in apparatus. If I placed the potato chip into the test tube first and placed the bung on, I could then inject the hydrogen peroxide, perhaps with a syringe, into the test tube. Using this method would prevent me from losing any gas so my results would be more accurate. 1 Lottie De Souza ...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. How Concentration affects the rate of reaction.

    There was also an unpleasant smell of Sulphur. After the liquid had evaporated there was a yellow layer of a substance at the bottom of the container. I collected 4 sets of results in total to give as many reliable results as possible.

  2. Investigate the effect of changing substrate concentration on the rate of the reaction between ...

    However, there came a certain concentration where the rate dropped and then increased again at a higher concentration. I had not foreseen this when planning my investigation and these results do not agree with my prediction. Then again, this change happened in only two out of the three attempts made

  1. Enzymes - show how substrate concentration affects the rate of reaction for an enzyme ...

    Predicted Graphs: V-max Rate of Reaction (cm�/s) Substrate concentration (mol/dm�) The graph above shows that as the H2O2 concentration increases, the rate of reaction also increases. This is because if there is more substrate, H2O2 then it will mean that there will be a greater chance of frequent collisions between the H2O2 and catalase.

  2. The Effect of Catalase in the Breakdown of Hydrogen Peroxide

    This time limit will be constant. When recording this vital data, the time limit (every two minutes) is very important to watch over. This is because if the time limit is extended it allows more oxygen particles to be released, therefore; the end results would be inaccurate and unfair.

  1. Investigation into the effect of substrate concentration on the rate of hydrogen peroxide decomposition ...

    Repeat procedure another two time for this particular concentration and then move on to the next concentration. Reliability - Fair test The method devised for this experiment eliminates the effects of other variables on the rate of this enzyme-controlled reaction, this means that reliable results are able to be obtained.

  2. Factors Affecting the Rate of Catalytic Decomposition of Hydrogen Peroxide.

    Mass Lost (g) Mass Lost (g) Mass Lost (g) 5 0.04 0.05 0.05 10 0.08 0.09 0.09 15 0.10 0.10 0.10 20 0.13 0.13 0.13 25 0.15 0.15 0.15 30 0.17 0.18 0.18 35 0.20 0.21 0.21 40 0.22 0.23 0.23 45 0.24 0.23 0.24 50 0.24 0.25 0.25 55 0.25 0.26 0.26 60 0.25 0.26

  1. The effect of concentration on the activity of catalase.

    10cm3 syringe --> Will be used to measure the necessary amount of buffer solution 5. Buffer Solution --> Will be used to keep the pH constant. A pH of 6.3 was used as catalase works best at acidic conditions.

  2. Effect Of Substrate Concentration On The Activity Of Catalase

    If the catalase was used up then another potato would have to be crushed and this could produce catalase of a totally differen from studentcentral.co.uk t concentration which would lead to inaccuracies in the experiment making this an unfair test.

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