Rates of reaction - kinetics (A2)
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I'm doing an experiment on rate of reaction between hydrogen peroxide and iodide ions. How would I carry this out using titration?
Ulex replies
I really think this is for you to decide! I’ll give you a few hints to start you thinking.
The reaction actually involves a third reactant; it takes place in the presence of acid – sulphuric acid is probably best since, in dilute solution, it will not oxidise anything in the mixture nor be oxidised by anything in the mixture.
The obvious way to investigate the rate of reaction is to mix the reactants and at measured time intervals withdraw samples, neutralise with, say, sodium hydrogencarbonate which quenches the samples and titrate the iodine in the samples with sodium thiosulphate.
There is a very elegant method using this principle which goes by the name of the Harcourt-Esson experiment; try looking it up and see if the idea appeals.
Since iodine solution has a yellow colour you might consider using colorimetry as an alternative to titration.
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updated: 07 March 2006
