Practical investigations
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For my chemistry coursework I am investigating the reaction of hydrochloric acid and magnesium and ethanoic acid and magnesium and their corresponding activation energies. For my coursework I am required to work out percentage error but I am not entirely sure how to work this out. As far as I know it is to do with the limitations of the equipment [I think] and I will work them out for my minimum and maximum values. And also is it possible to tell me how to do a correlation coefficient graph to plot my workings out?
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Ulex says
You seem to have the right idea! Taking the example of the Arrhenius plot for activation energy, estimate the maximum value reasonable for each measurement and work out values of ln(rate) and 1/T using these values instead of your actual ones. Plot the results on the same graph as your real results. Do the same for minimum possible values.
Draw best straight lines for both of these sets of values and work out a maximum and minimum value for the activation energy. This will give you a +/- error range.
I am not at all sure that correlation coefficients help here and I am not an expert. There is what looks like a useful exposition on the first website to show when you enter 'correlation coefficient graph' into Google.
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updated: 18 March 2009
