The rate of reaction Essay Example for Free

The rate of reaction Essay Add 50 cubic centimetres of hydrogen peroxide to a conical flask Add liquidised celery solution to hydrogen peroxide and place bung over conical flask After 30 seconds, see how much oxygen has been produced Celery Concentrations Volume of Celery (cm3) Volume of water (cm3) Concentration of celery (%) 80 20 80 60 40 60 40 60 40 20 80 20 Results Tables First Repeat Time (seconds) Celery Concentration (%) Amount of hydrogen peroxide (cm3). Volume of oxygen produced (cm3) Second Repeat Time (seconds) Celery Concentration (%) Amount of hydrogen peroxide (cm3) Volume of oxygen produced (cm3) Third Repeat Time (seconds) Celery Concentration (%) Amount of hydrogen peroxide (cm3) Volume of oxygen produced (cm3)Â   Averages Time (seconds) Celery concentration (%) Amount of hydrogen peroxide (cm3) Volume of oxygen produced Analysing evidence and concluding From the graph I have drawn using the above table of averages, I can see that as the concentration of the enzyme catalase increases, the amount of oxygen produced also increases. I can also see from my table of results that as the concentration of the enzyme increases, the volume of oxygen increases. This shows that the rate of reaction increases, which supports my prediction. The reason for this is the Collision Theory, as stated in my prediction. The Collision Theory states that the more particles there are in a solution or area, the higher the rate of reaction will be because there are more particles, therefore there are more collisions, meaning there is an increased chance of successful collisions in which the two particles react. In this experiment, when the particles react, they break down the hydrogen peroxide and create oxygen and water. As the volume of oxygen increased with positive correlation to the amount of the enzyme in the mixture, I can see that the rate of reaction was increased, thus proving my prediction to be correct. Please see also attached graph. Evaluation The experiment was relatively easy, in that the variables were easy to identify, control or measure, which means that the readings from the experiment should be very accurate. The apparatus was set up in such a way that I think the results are very reliable. The tubing and bung all fitted well into their respective receptacles, thus no oxygen could have escaped from there. The only time and place the oxygen could have escaped was the period between adding the liquidised celery to the hydrogen peroxide, and placing the bung into the conical flask containing the mixture. Unfortunately, there was nothing I could do to stop this, except try and replace the bung as quickly as I could. There do not seem to be any anomalous results, except in the third repeat when I was using a concentration of forty percent celery. After ten seconds, I measured no oxygen whatsoever, and I presume this was due to a fault in the tubing; perhaps there were slight gaps that I had overlooked during that repeat. However, as this is the only time there is an anomaly within the results, I must assume that the rest of my results are accurate and reliable, and therefore the equipment was set up correctly and performed well. I think that my results are sufficiently reliable to support my conclusion (see above) because they match my prediction and scientific knowledge of this subject, and the figures I have obtained seem reasonable. I know they are accurate because I was careful to be accurate when taking readings from the gas syringe, and I am sure they are reliable because they do match scientific theory, as taken from text books, etc. , and my prediction, which was made using scientific knowledge from various sources. To improve the reliability of the experiment, I think it would be necessary to find a way of feeding the celery into the conical flask, perhaps via another tube system, where it would be possible to add the celery to the hydrogen peroxide without losing any of the oxygen produced.