The nature of the mixed gas depends on the type and composition of the constituent gas. There are 3 ways to express the composition of the mixed gas.
①Volume composition: the ratio of the sub-volume of the constituent gas to the total volume of the mixed gas, expressed by ri
The so-called sub-volume refers to the volume occupied by the component gas alone under the temperature and total pressure of the mixed gas.
② Mass composition: the ratio of the mass of the constituent gas to the total mass of the mixed gas, expressed by wi
③Mole composition: Mole is the unit of quantity of matter. If the number of basic units (which can be atoms, molecules, ions, electrons or other particles) contained in a system is equal to the number of carbon-12 atoms in 0.012 kilograms, the amount of matter in the system is 1 mole. The ratio of the moles of the constituent gas to the total moles of the mixed gas, expressed by xi.