Date of publication: 2017-07-08 19:53
It is best, if possible, to have all the average results points plotted on the same graph for easy comparison - take care because this may involve 9 or 5 lines for 9 or 5 different acid concentrations Make sure you use a clear KEY for the different line points and a clear title for the graph AND clearly label the axis including the units or whatever.. Use smooth 'best curves' for as many of the points as possible, though some parts of the graph might be linear, watch out for the 'scatter' - the experiment is not that easy to get good results.
So what we are after is the main 'trend(s)' or 'pattern(s)' describing with reference to the graphs. Does the 'trend' of all the graph lines support you're your prediction, are all the results consistent with your prediction AND theory?
To ensure that this experiment is fair I will control the variables, . I will keep everything constant apart from the variable I am changing-temperature. Therefore, I will make sure that I only change the temperature of the reaction mixture and keep the volume and concentration of the sodium thiosulphate, the volume and concentration of hydrochloric acid and the pressure of all the mixtures the same.
For different the acid concentrations you can do a 7nd and more advanced graphical analysis of the limestone results. This involves measuring from the graph, the speed of the reaction at the start. Explain why best data at the start? (. first 8-5 mins?).
Briefly explain how the method can be used to measure the speed - the results of the first few minutes is usually the most crucial - you can discuss (briefly) other methods, but perhaps better in evaluation as a means of further evidence.
The graph above is the average time taken for the solution to become cloudy. It also has a line of best fit to show the consistency and accuracy of the results. There are no anomalous results which shows that the experiment was very accurate. Furthermore, the graph is a perfect curve
This report briefly touches on all the main elements necessary. However it lacks depth and detail. In order to be successful more data should be collected and evaluated. Specific strengths and improvements have been suggested throughout.
However, the second part of my prediction that for every increase of 65°C the rate of reaction is roughly halved, is only true in some places. For example, when the temperature is 95°C the reaction took seconds and when the temperature was 55°C the reaction took 69 seconds which is roughly half the time. In contrast, when the temperature was 5°C the reaction took 795 seconds, and when the temperature was increased by 65°C to 65°C the reaction took seconds, which is not half or even roughly half 795.
It is obvious that there is a general trend in the results. As the temperature increases, the time taken for the sodium thiosulphate solution to become cloudy decreases. This is because as the temperature increases, the reactant particles move more quickly. In addition to this, more particles have activation energy. This means more of the particles collide and more of the collisions result in a reaction, so the rate of reaction increases.