Avogadro's law is part of the famous ideal gas laws. It was formulated for the first time by the physicist Amedeo Avogadro, who through his theory about the amount of molecules in gas samples, manages to explain how gases mix, keeping a simple proportion between them.
Avogadro supports his hypothesis in the studies that existed until that moment on gases and in the results obtained in his experiments.
Avogadro formulates the following postulate in 1811:
" Similar volumes of gas of different substances, when calculated under equal conditions in pressure and temperature, present the same amount of particles."
Why does this happen?
When increasing the amount of gas within a container, will be more molecules, which cause a rise in the frequency of collisions against the walls of the container, which leads to the pressure within the container is much greater than the outer one, causing the plunger to go up suddenly. Now, as there is a greater volume of the container, the amount of collisions of the molecules against the container wall will drop and the pressure will return to its original value.
Several years passed for Avogadro to recognize the existence of gaseous molecules comprised of more than two similar atoms. According to him, during a chemical reaction, a reagent particle should be reactivated with more than one particle of another reagent, giving rise to one or more product particles, but a particle cannot be reactivated with an inaccurate number of particles.
Avogadro's law has been very important for science since it allows the transformation of matter to a certain amount of particles.
