After the measuring cylinder accurately measures the volume of each concentration, I will place a piece of magnesium ribbon, which has been cut down to 1cm, into each beaker. I will have six stop clocks to measure how long it will take for the magnesium ribbon in each beaker to disappear. In order to get accurate results; I will have a range of six different concentrations of hydrochloric acid, keeping the surface area and temperature the same.
To make this a fair test, I will control the surface area of the magnesium ribbon by making sure the length each ribbon is the same. I will also keep the volume the same in each beaker, in order to get fair results. I will then repeat the experiment to find any anomalous results. To make sure that the experiment is safe and accurate, I will clean all the apparatus before using them and make sure the hydrochloric acid I use is not contaminated; so as to get accurate results. I will time how long it takes for each magnesium ribbon to disappear, and write out the results on a table.
Results:
Experiment 1:
- I repeated the experiment to find any anomalous results.
Experiment 2:
Conclusion:
As shown in the graph my conclusion went according to my prediction. The magnesium ribbon in the highest concentration of hydrochloric acid disappeared fastest out of the other concentrations. When reacting with the acid, it caused white puffs of smoke to be let off; (hydrogen gas- tested using delivery tube and a lighted flint). I also observed that the ribbon moved around the beaker fizzing and producing a lot of bubbles. This is because the rate that the particles are reacting is so fast that the ribbon is whizzing around colliding with the acid, giving off hydrogen.
The ribbon in the lowest concentration of hydrochloric acid took the longest time to disappear. When reacting with the hydrochloric acid, I observed very little reaction. There were a few bubbles and hardly any movement and there was no visual of hydrogen gas being given off. This could be because the rate of reaction is so slow that there is hardly any collision with the acid, thus none of the particles were being lost.
As shown in the results that have been gathered I noticed that the higher the concentration of the hydrochloric acid the faster the rates of reaction of the magnesium ribbon. This is because there are more particles of the reactant knocking between the acid, which makes the rate of collisions much higher.
I also noticed that the lower the concentration of the hydrochloric acid, the slower the rate of reaction of the magnesium ribbons. This is due to the fact that the number of particles in the acid is less, so the rate of collisions with magnesium is much lower.
Evaluation:
The experiment went according to plan, with the results matching my prediction. However, when recording the results the stop clock sometimes stopped working and I had to repeat the test. As shown in the graph titled ‘Experiment 2’, the magnesium ribbon had taken less time to disappear than the ribbon in ‘Experiment 1’ in the concentration of 0.2M hydrochloric acid. This was as anomaly and could have been because of the hydrochloric acid being contaminated or the measurements of the ribbon being inaccurate. Apart from that, the average of the set of results was quite realistic.
I could improve the whole investigation if I were given the chance by first making sure all the equipment being used is in proper working condition. In this case, the stop clocks. I could also have two stop clocks testing the same rate of reaction to get accurate results. I could further test the reliability of the experiment by repeating the test several times.
The investigation was quite successful and some patterns, as mentioned in the conclusion, were found explaining how different concentrations effected the rate of reaction.
To further extend this investigation, I could continue testing how different concentrations effect the rate of reaction but this time make the concentrations higher. I could also bring other factors, which effect the rate of reaction, such as catalytic factor, surface area and/or temperature factor.
I would consider the temperature factor, as it is more efficient. If I increased the temperature in an experiment, there will be more particles colliding with enough energy to make the reaction happen, the initial energy is known as the activation energy. An example of an experiment that could demonstrate how this would work would be when baking a cake. The hotter the oven the quicker the cake will bake. Another example would be when considering enzymes. The temperature has to be considered so to give maximum yield and not denature the enzyme. An example of this would be when baking bread; the yeast is placed in warm enough water, so that it could start to fermentate. However, the temperatures should not be too high or else the yeast would denature.
By Samira Quraishy.
