Investigation into transition metals as catalysts Essay Example for Free

Investigation into transition metals as catalysts EssayHydrogen peroxide decomposes slowly to form pee and oxygen gas. Transition metal oxides depart catalyse this reaction. A catalyst speeds up a reaction with come in cosmos employ up. The best catalyst for a reaction increases the rate of reaction the most. The rate of reaction can be measured by the amount of product organize divided by the time of the reaction. If 40 ml of oxygen were produced in 30 seconds (0. 5min), then the rate of reaction would be 80 ml/min. Planning- the mechanism available will be20 volume hydrogen peroxide solution (irritant), copper dioxide (harmful), iron oxide, atomic number 25 dioxide (harmful), spatulas, ele4ctronic balance, measuring cylinder, trough (water bath), stop watch, thistle funnel, preservation tube, bungs to take funnel and tube, boiling tubes. Safety Precautions Wear goggles. Make sure that the hydrogen peroxide does non make contact with skin and/or hair. traverse bench thoroughly after experiment. Variables Each catalyst should be tried twice, however the catalyst should be altered after each experiment. Constants.Volume/ niggardness of hydrogen peroxide (10cm3 of 20 vol. hydrogen peroxide + 10cm3 of water). Amount of each catalyst (1g). Time left for/intervals at which gas is measured (every 5 seconds for 50 seconds). Same general apparatus. NB. Wash apparatus after each experiment. Measurements The volume of gas (oxygen) produced will be measured during each test at 5-second intervals- this will be d unrivalled by measuring how much water is displaced in the measuring cylinder by the gas. Each catalyst will be tested twice, and the test will last for 50 seconds on each occasion. Results Manganese.Time (secs) Experiment 1 (vol. of type O cm3) Experiment 2 (vol. of group O cm3) Average (vol. Of Oxygen cm3) Copper Time (secs) Experiment 1 (vol. of Oxygen cm3) Experiment 2 (vol. of Oxygen cm3) Average (vol. Of Oxygen cm3) Iron Time (secs) Experime nt 1 (vol. of Oxygen cm3).Experiment 2 (vol. Of Oxygen cm3) Average (vol.Average rate of reaction Average rate= volume/time=.. cm3/sec Manganese dioxide= 96/40= 2. 4 cm3/sec. Copper oxide= 27/50= 0. 54 cm3/sec. Iron dioxide= 27/50= 0. 54 cm3/sec. 20 vol. of hydrogen peroxide means that each cm3 gives off 20 cm3 of oxygen gas. We diluted it to 10 vol. Using water and so we would bring forth expected deoxycytidine monophosphate cm3 of oxygen. Hence manganese dioxide as well as being the best catalyst also caused more hydrogen peroxide to break down.Evaluation Although the dissolvents obtained were fairly good, there were quite a few problems during the experiment, which affected them. These were It was rocky to fill the measuring cylinder with water, as well as insert it into the trough (water bath) without any escaping and creating difficulties in measuring the gas produced. The largest measuring cylinder was and 100 cm3. This was very relevant as one of the tests for manganese dioxide exceeded 100 cm3 in gas produced, therefore a larger cylinder was needed.The catalysts were very beautiful powders, which made it difficult to measure out exactly 1g. When gas was being produced and coming off fast, it was difficult to read the measurements accurately as the climb of the water wasnt steady. (It was also difficult when a gas bubble came up while the gas volume was being measured). In act to improve the experiment and frankincense make the results more accurate, the following could have been done A wider measuring cylinder used so that gas being produced rapidly would not flummox the water surface as much, making the volume of gas easier to measure.A larger measuring cylinder used so that gas volumes exceeding 100 cm3 could be measured and therefore the results not interrupted with. Repeat testing (i. e. 3 tests for each catalyst) carried out so that there is less room for delusion whilst obtaining results. This would also make them more reliable. When the results were obtained, there were some noticeable abnormalities i. e. anomalous results. These were the measurement of gas after 5 seconds when testing iron dioxide, and the tests when using manganese dioxide.This was because when manganese dioxide was being tested, there were large differences in measurements at each time interval, therefore experimental errors must have occurred (after 40 seconds on the initiatory test, the gas volume also exceeded 100 cm3, whilst in the second test this did not happen until after the 50 second limit). The other anomalous result was when testing iron dioxide, as after the first 5 seconds, there was a large difference in the volume of gas between the 2 tests carried out (30 cm3 20 cm3).The cause of these anomalous results is most likely related to the surface area of the catalyst in correlation with each test carried out i. e. the powdered catalyst may have been slanted up the boiling tube during one test, but not on the other, resulting in diff erent surface areas. Shaking the boiling tube before each test and/or using a wider testing tube, could have however prevented this. From the results obtained, you can also not definitely state the best catalyst for his reaction, as all 31 transition metals were not tested.Therefore to extend this investigation to find the best catalyst for producing oxygen gas from hydrogen peroxide solution, all the transition metals could have been tested as well as repeat tested for verification. This, in conclusion, would have found the best catalyst for this particular reaction. Daniel Powell. 10k. 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.