I want to calculate the activation energy of the decomposition of sodium thiosulphate, as a part of my school research project. I am aware that I must use the Arrhenius equation where the rate of reaction is measured at different temperatures. I will be using HCl as the acidified solution.
The problem which I am facing is in measuring the rate of reaction. The standard method is to use measure the time taken for the sulphur precipitate to cover a 'mark' which is placed at a specific position on the conical flask. This method only provides the time, which can be converted to 1/time. Is this suitable for the Arrhenius equation? If I need the rate in terms of mol/s*dm^3, what method can I use to measure the change in concentration?