Equal volumes of all gases, at the same temperature and pressure, contain the same number of molecules. This principle establishes a direct proportionality between the amount of a gaseous substance and the volume it occupies when conditions such as temperature and pressure are held constant. For instance, if one doubles the amount of gas in a container while maintaining a constant temperature and pressure, the volume of the gas will also double.
This fundamental concept in chemistry provides a critical link between the macroscopic properties of gases (volume) and the microscopic world of molecules. It has been instrumental in determining the molar masses of gases and in understanding the stoichiometry of reactions involving gaseous reactants and products. Historically, this understanding contributed significantly to the development of the atomic theory and the establishment of consistent methods for quantifying matter.
