Generalities on measuring methods

A chemical transformation depends on temperature, concentrations and time. The measurements are therefore generally carried out at a constant temperature and at different times. There is no method by which to directly measure the kinetic properties of a reactioa The measurement methods are most often performed by the measurement of quantities that are related to the extent or fractional extent versus time, and we thus obtain the integral curves. The derivation of these data with respect to time leads to the rate of transformation at any time and then to the different derivative curves. 

Kinetics measurements are generally carried out in difficult conditions because the experimenter has to meet extremely strict conditions  

We will distinguish two categories of methods chemical methods and physical methods. 

For example, Bodenstein studied hydrogen iodide decomposition according to  

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