Proust's law is one that expresses that the relative number of the elements formed within a compound are kept constant, without taking into account the origin of said compound. This law was proposed for the first time by the French chemist Louis Proust in the year 1795.
Proust carried out much of his research in Spain and it is there that he succeeds in determining that the mixture of elements can be carried out in a continuous weight ratio regardless of the immediate process that formed it. That is, the elements that make up a compound will retain a fixed proportion by weight, within any net sample of a mixture. A simple example of this law is the case of water, it is made up of two elements: hydrogen and oxygen, which will always be in a ratio of 1-8, regardless of the origin of the water.
Through this law Proust also demonstrated that the theory of the chemist Berthollet was incorrect, since he claimed that some chemical mixtures could vary in their composition, depending on the way they were prepared. Proust attributed this mistake to the misuse of substances chemicals that were not of the whole purified. Proust's success was more than evident and his theory was definitively established, thanks to the support of another chemist named Jons Berzelius, who supported his hypothesis, which was unanimously accepted.
Proust's law guaranteed the proportionality between the mass of reactive substances and the products in a chemical reaction. This is why it was also known as the law of definite proportions.
For industry and the laboratory environment, these laws are very useful in calculating the amount of reagents required for the preparation of substances, as well as the number of products that must be produced.
