When new molecules are produced by the success of the collision with activation energy, it is called ‘activated complex’. This investigation is being carried out to test if the rate of reaction between ml of sulfuric acid and 0. Egg of magnesium will increase or decrease when the surface area of the magnesium varies, when the mass stays the same. In this investigation the sulfuric acid will have a tube connected to it and to a measuring cylinder filled with H2O (see images 1 and 2).
This is to visibly see when the reaction between the sulfuric acid and the magnesium happens, because the gas created from the reaction will push the water out from the measuring cylinder and into the bucket it is connected to (again, refer to images and 2 for visual aid). Once the water has been pushed to the ml reading on the measuring cylinder the time is stopped and the reaction is measured. This is what will happen in the investigation, and why the investigation is taking place is to see if the surface area will have an effect on the rate of reaction.
Research question/statement: The purpose of the experiment is to test if the surface area of magnesium will affect the rate of reaction when added to 0. MM sulfuric acid. The changes of the independent variable will affect the dependent variable because the surface area will have an affect on the possibility for particle collision which activates the reaction. Hypothesis: The magnesium with the greater surface area will have a larger reaction rate due to a higher frequency of particle collisions.
When there is a larger surface area there is a higher possibility for particles to collide and since the reactions happen more when particles collide there is more chance that the molecules will collide thus leading to a faster reaction rate. Apparatus: Image 1 Image 2 Variables: Independent variable: The surface area of the magnesium will be changed but the magnesium will have name mass. This will be measured by using the scale (В±0. 01 g) to take the mass of the magnesium, and a ruler (В±O. CM) to divide the magnesium into smaller pieces for a larger surface area.
For example, in one trial the magnesium will be 0. Egg (approximately CM) and added to the sulfuric acid (ml В±O. Ml) as a whole piece, the next test the magnesium will be 0. Egg (approximately CM) but cut in halve, and in the third test the magnesium will be 0. Egg (approximately CM) but in quarters ” and there will be multiple trials for the different surface areas to ensure the results are reliable. Dependent variable: The time taken for the reaction between the magnesium (0. Egg В±0. Egg) and the sulfuric acid (ml В±0. Ml) is the dependent variable.
It will be measured using a stopwatch (В±0. 01 s). Controlled variable: I Variable I How maintained I How measured I I Volume of the sulfuric acid will be I For each trial ml of sulfuric acid will I It will be measured using the measuring I Controlled be used I cylinder (В±ml) I I Temperature of the room to ensure the The solutions will be left out in room I It will be measured by not changing the Temperature of the solutions is consistent I enrapture – no incubators or ice baths FL air-con/heater temperature; also a Lana kind will be involved.
The I thermometer will be used to check the I be altered I temperature of the solution throughout the experiment; causing minimum I I temperature change for the solutions. I air-con/heater will not I I The size of the plastic tube will be the same plastic tube experiment an affect on the I reaction I The same tube will be used throughout the Bib using I I controlled because the diameter and length I I loft the tube might have Irate of I Imams of magnesium will be controlled 1 0. G of magnesium (approximately CM) will Will be measured by taking the mass on the I I I be used for each testing I scales (В±0. 01 g) The results are ensured to be reliable because the tests for each piece of magnesium will be trialed three times to ensure that the results are accurate and precise. Materials: I Equipment I Magnesium В±O. Egg CM) Large В±o. Ml Tube 19 moll I Size 1 0. Egg (approximately I Water bowl I I Measuring cylinder 12 CACM moll II Stopwatch В±O. Ass I I Volumetric flask I Sulfuric acid I I Safety equipment (goggles, apron) I Ruler В±0. CM I Scale В±0. Egg CACM I Quantity Method: I I Thermometer В±0. ICC 1. Set up apparatus as shown in image 1 2. Measure ml of 0. 8 sulfuric acid using the measuring cylinder and pour it into the volumetric flask 3. Confirm that the water in the tub is at room temperature by using the thermometer to verify that the water is at room temperature (around ICC) 4. Ensure that there are not any air bubbles in the volumetric flask that is held up by the retort stand and make sure the rubber tube is at least half way up that particular measuring cylinder 5.
Cut the 0. Egg of magnesium into either 1/2, 1/4, or 1/12 and keep the pieces in a ml beaker 6. Pour the magnesium from the beaker into the volumetric flask containing the sulfuric acid 7. Quickly connect the tube (which is in the red stopper) to the magnesium and sulfuric acid solution and start the stop watch when the red stopper is in place covering the volumetric flask 8. Collect the data by using a hand drawn table then paste the collected data onto a properly drawn up table on excel. 9.
Graph: As shown in the graph the 0. Egg of magnesium that was cut into smaller pieces has a trend of having a faster rate of reaction than the 0. Egg of magnesium that was cut in half. The relationship of the middle point relating to the two outer points shows that it is an outlier; the point is not particularly close to the line of best fit whereas the other two points are inline with each other. Conclusion and Evaluation: The purpose of the experiment was to test if the surface area of magnesium affected the rate of reaction when it was added to 0. M sulfuric acid. When referring to the results it is obvious that there is a great difference in the results when there is less surface area, specifically when the magnesium is in half and in twelfths – there is a ass difference. The results support the hypothesis because the experiment shows that the more surface area the magnesium had, the faster the reaction occurred with the sulfuric acid; this happened due to the higher frequency of particle collisions. The practical could have had multiple errors, the uncertainties with the materials, and also human error.
For example, starting and stopping the stop watch at different times for each trial, this creates an unfair and unreliable investigation because some of the trials may have had the stopwatch start or stop earlier than other trials. Plus human reaction time would also play apart in the scenario; humans tend to have a general reaction time of about 215 milliseconds, which could have a slight affect on the results. Another valid point that would have lead to error is that some of the magnesium ices used throughout the experiment were rusted (these pieces were used without knowing that they were rusted).
Therefore the pieces would have reacted slower and might not have fully submerged in the sulfuric acid, thus meaning that there is less surface area for the sulfuric acid to react with, creating a slower reaction. In the future to make sure this mistake does not happen again, all the materials should be checked for quality beforehand to make sure that they are in an appropriate shape to use. In the method it is very difficult to drop the magnesium into the sulfuric acid, specially when it is in pieces – some of the pieces were getting stuck to the beaker while some pieces were already in the sulfuric acid.
This is another possible point of error because whilst some of the pieces were reacting the red stopper wasn’t on to capture the gas since some of the pieces were still being prodded to get out of the beaker – valuable reactions (of the hydrogen gas being contained) would have been lost from the pieces that already started the reaction, and this would have had an effect on the time. To improve this, tweezers could have been used to hold the magnesium in one place then roped into the sulfuric acid; that way all the pieces would have hit the sulfuric acid at about the same time.
During the experiment the equipment was in good shape and there were not any fluctuating moments. However the red stopper popped out of the volumetric flask due to the build up of hydrogen gas in one of the trials and therefore the trial had to be restarted. Overall, to improve the investigation the mass of magnesium used would be increased because it would be easier to see a clearer difference in time if there was a large surface area to work with as it could be altered with a more significant difference.