Rates of reaction - kinetics (A2)
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I have done the iodine clock experiment with peroxodisulphate ions. I have all my results but I am a bit confused about finding the activation energy for the reaction by using the Arrhenius equation.
I have done: Ln(k) in the y axis, and 1/T on the x axis, but I have seen a graph where
ln(Rate) is used instead of ln(k), so I don’t know which one to use.
Igloo writes ...
In the context of your experiment the rate of reaction is proportional to the rate constant, k, so you can plot either of these against 1/T. After all you will be measuring the gradient of the line, and this will be the same whichever of these plots you use.
Using “rate” is much easier, because it is proportional to (1/time), and since you have been measuring times for your clock reactions this is surely the easier approach. All you have to do therefore is to calculate ln(1/time) for each experiment and plot these values against 1/T.
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updated: 01 December 2006
