To investigate the factors that affect rate of reaction Essay Example for Free

To investigate the factors that affect rate of reaction Essay I will pour one lot into the glass phial, I will then measure out five different concentrations of acid. I will do this by using a two molar acid and will vary the ratio of water, the combinations will be: Acid Water 25 ml 0 ml = 2 molar 15 ml 5 ml = 1. 6 molar 12. 5 ml 12. 5 ml = 1. 2 molar 10 ml 15 ml = 1 molar 5 ml 10 ml = 0. 8 molar Then I will pour the two molar acid into the phial, put the cork on and start the timer as soon as the cork is in place, so we are able to start timing when gas is being collected and not before as this would make it an invalid result of the first ten seconds. I will repeat this process for each concentration. After each experiment I will rinse out the phial, to make sure the marble chips wont start reacting before I pour the acid in. I will record the measurement from the syringe every ten seconds by folding the tube over to stop the gas from escaping through, and will empty the syringe of gas after each experiment. Trial Run Below is a results table showing our first trial run of our plan of action so I can see if anything needs changing. Concentration g/dm3 Time (s) 2 molar 1. 6 molar 1. 2 molar 1 molar 0. 8 molar. These results do follow the pattern predicted so I will not change my plan of action for the real experiment. Apparatus . 5 measuring cylinders to measure out the different concentrations . Water . 2 molar acid . syringe to measure the gas produced . 5 lots of small marble chips each weighing 2. 5 grams . Electronic weighing scales to weigh out the marble chips. 5 beakers to hold the marble chips . Rubber tube with a cork attached to capture the gas produced . A phial to hold the marble chips with the acid whilst reacting . Stop clock to take readings every 10 seconds Fair Test I will make sure it is a fair test by rinsing out the phial after each reaction has taken place so the next lot of marble chips wont start reacting before the experiment begins. I will use the same bottle of 2 molar acid to make sure I dont use slightly different concentrations and will repeat the experiment three times to get a good average of the results. Also I will use the same measuring cylinders so I will be measuring to the same nearest ml each time. Method . Make sure you have all the equipment stated in apparatus list . Weigh out five lots of 2. 5g of marble chips . Measure out the five different concentrations . Pour one lot of marble chips into the phial . Pour acid in the phial with the chips and place on the cork . As soon as cork is in place start the stopwatch . Every 10 seconds record the gas measurement from the syringe . Rinse out the phial and repeat for each concentration . Record all results on a table SAFETY BOX. Wear goggles and aprons to protect from acid spillage . Keep lid on acid when not in use . Make sure bags and coats are out of the way Results Concentration g/dm3 Time (s) 2 molar 1. 6 molar 1. 2 molar 1 molar 0. 8 molar Concentration g/dm3 Time (s) 2 molar 1. 6 molar 1. 2 molar 1 molar 0. 8 molar Average Results Here is a table showing the average of the three sets of results that I have recorded: Concentration g/dm3 Time (s) 2 molar 1. 6 molar 1. 2 molar 1 molar 0. 8 molar   Results Table for Rate Of CO2 Production Concentration g/dm3 ( Rate Of CO2) Time (s) 2 molar 1. 6 molar 1. 2 molar 1 molar Evaluation Overall I think that my results are reliable but not as accurate as they could be. Reasons for this are that the measuring cylinder for measuring the acid and water was only accurate to 0. 5ml and the syringe to measure the production of CO2 gas was only accurate to 1ml, or more with the human eye reading it. The balance to weigh out the small marble chips was very accurate to 0. 01g but there was no guarantee that the surface area was the same which will have affected the results. Starting the stopwatch at exactly the same time for each experiment was impossible and will have varied each time affecting the first 10 second readings. In my theory I mentioned about temperature effecting the rate of a reaction, and the room temperature wasnt the same each day during the experiment so this will also have added inaccuracys. Due to human error the gas may have leaked out through the tube whilst we were trying to read from the syringe resulting in us reading more then what we should have. With all this taken into account I have concluded that although my results follow the patterns and trends predicted they arent very accurate. If I was to do the experiment again then I would have the same amount of marble chips as well as the same weight as this would make the surface area more accurate. I would also do the experiments all in one day so that the temperature would be roughly the same. Also I would probably use a different method of tracking the mass instead of displacement. I would do this because although displacement is very clear and simple, it can also be very inaccurate and is read through the human eye, whereas mass loss would be done with a machine and would be extremely accurate. I have found no anomalous results as each graph follows the trends and patterns expected. My graphs clearly illustrate that my theory was correct. The collision theory in particular as this was the factoral that we were changing (concentration). The higher the molarity the more particles there were in the same volume of water so the faster the reaction. As you can see from my graphs that the higher the molarity went the faster the gas was produced. Conclusion In conclusion the experiment went very well and I have proved that my theory was correct and that my results are reliable. You can see this from the graphs present. 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.