A with X-ray diffraction

X-ray diffraction using diffraction peaks suitable for each solid phase makes it possible to know the amount of each of these phases at a given time. This is a discontinuous measurement. 

General expression of the intensity change of a diffraction peak of the reactant solid 

We measure the ratio of intensity / of a peak, at time t, in the diffractogram of A to intensity f of the same peak at the beginning of the reaction. This ratio is equal to the ratio of the amount of A present at time t and the initial amount of A  

In the example of the meehanism previously mentioned for the oxidation of magnesium (section 7.2.2), sohd A is magnesium and that only step ([7. Et a4]) used this metal in the first member. The application of [11.7] thus gives  

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