The Avogadro-Ampere Law

Under isothermal and isobaric conditions (i.e., at constant T and P), equal volumes of gases contain equal numbers of atoms or molecules. 

The proportionality constant is independent of the identity of the gas. Some examples of molar volumes of an ideal gas at various T and P conditions are presented in Table 19.3. 

One important practical consequence is that mole fraction and volume fraction are identical quantities for ideal gases. 

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