Amedeo Avogadro Amedeo Avogadro Amedeo Carlo Avogadro, () Count of Quaregna and Cerreto (9 August 17769 July 1856), was an Italian scientist, most noted for his contribution to molecular theory now known as Avogadro's law, which states that equal volumes of gases under the same conditions of temperature and pressure will contain equal numbers of molecules. In tribute to him, the number of elementary entities (atoms, molecules, ions or other particles) in 1 mole of a substance, , is known as the Avogadro constant, one of the seven SI base units and represented by "N". Lorenzo Romano Amedeo Carlo Avogadro was born
Amagat's law pressure, the sum of which is the total pressure. Amagat's law assumes that the volumes of the component gases (again at the same temperature and pressure) are additive; the interactions of the different gases are the same as the average interactions of the components. The interactions can be interpreted in terms of a second virial coefficient, B(T), for the mixture. For two components, the second virial coefficient for the mixture can be expressed as: where the subscripts refer to components 1 and 2, the X's are the mole fractions, and the B's are the second virial coefficients. The cross term,