Rate of reaction Essay Example for Free

Rate of reaction Essay Evaluation: I think that overall, our experiments/investigation was successful except for minor things such as the occasional odd results. On the first graph, these can be identified as when the lines representing 1. 25 and 1. 5 molar kept on crossing over each other. They were very similar. In theory, all the lines should be apart because the rate of reaction should be increasing every time. Another odd result is that on the second graph, the point which represents 1 molar is no where near the line of best fit. All points should either lie on the line or be pretty close to it. I believe that we got these odd results because our human errors. We may not have collected all the gas produced. Or the gas could have been caught in the collecting tube and this may have resulted in the long time needed for the reaction. I believe that the method provided with us has a few faults that I would like to point out. Firstly, when the magnesium piece is dropped first, then the acid poured, time is taken for the all the acid to drop but as soon as the first drop touches the magnesium it will react. This means that hydrogen gas would have been produced when pouring in the acid and lost through the open top. To change this, I would say in the method that the acid should be poured in to the test tube first then the magnesium piece, as the cork can be replaced without the metal touching the acid and no hydrogen gas would be lost. Secondly, gas can get trapped in the collecting tube as it faces down. When the first amount of gas is produced, it is followed by more which results in the gas pushing forward for more space because it cant be compressed. When the last amount of gas is produced, nothing is there to push it forward so it just floats around without reaching the measuring cylinder. I dont really have any improvements for the method but you could try to keep the measuring cylinder closer to the test tube and keep it at an elevated position. This way, more gas reaches it. We should have taken more care when handling the glass equipment as a measuring cylinder had been pushed over the ledge of the worktop and smashed when it had contact with the ground. Overall, the method was good but like everything else, it could be improved. It was generally a fair test but a few things may have altered the results, such as after a few of the first experiments, one of the windows was opened in the room and cold air rushed in. I dont if this had anything to do with the experiment but it could be something to think over when planning the next investigation. I feel that the measurements were easy to take measurements as we didnt miss a single reading. We could have repeated the experiment once more to be a little more accurate, the more results there are, the better it is after all. All the graphs showed a pattern to do with the concentration levels of the acids, the trends got higher for rate of reaction, the time decreased for stronger acids and less time was taken to. We kept the few odd results we got as it gave us something to talk about and think about in the future. I strongly believe that the results that we got, supported our conclusion as no matter whose results you saw, all showed the same trend and this proves that the results were reliable. Next time, I would use more concentrations of acids, so that we can be even more accurate and sure about the results. Further investigations you could think about could be changing the temperature of the experiment and investigate if it alters your experiments at all. You could also change the surface area of the metal such as having a block, or reacting it in a powder form. Catalysts could be added to the reaction to see if they show a major difference. Show preview only 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.