Approximate Equation to Calculate Partial Pressures in a Mixture of Real Gases

Autor/in	Hayez, Bernard
Titel	Approximate Equation to Calculate Partial Pressures in a Mixture of Real Gases
Quelle	In: Journal of Chemical Education, 95 (2018) 11, S.1982-1988 (7 Seiten)Infoseite zur Zeitschrift PDF als Volltext Verfügbarkeit
Zusatzinformation	ORCID (Hayez, Bernard)
Sprache	englisch
Dokumenttyp	gedruckt; online; Zeitschriftenaufsatz
ISSN	0021-9584
DOI	10.1021/acs.jchemed.8b00185
Schlagwörter	Chemistry; Science Instruction; Molecular Structure; Equations (Mathematics); Visual Aids + Suchen Sie Ihr Suchwort? Chemie; Teaching of science; Science education; Natural sciences Lessons; Naturwissenschaftlicher Unterricht; Equations; Mathematics; Gleichungslehre; Anschauungsmaterial
Abstract	From a physical point of view, the "partial pressure" of a component "i" in a gas mixture is defined as the contribution of molecules "i" to the force per unit area that the molecules of the mixture exert on the wall. The relation pi = x[subscript i]P (where x[subscript i] is the mole fraction of "i" and "P" the total pressure) is in agreement with this definition for perfect gases, but not for real gases. For lack of a general macroscopic equation for the partial pressure in real gas mixtures, the product x[subscript i]P is used as "operational partial pressure." Using the virial expansion applied to the equation of state of nonideal gas mixtures truncated to the second order, we obtain an approximate equation of the partial pressures for such mixtures. This equation allows for a comparison with x[subscript i]P as well as for the creation of diagrams expressing the total and partial pressures of the various constituents as a function of composition. Such diagrams prove useful to tackle this delicate subject with students, from a conceptual and from an educational point of view. (As Provided).
Anmerkungen	Division of Chemical Education, Inc. and ACS Publications Division of the American Chemical Society. 1155 Sixteenth Street NW, Washington, DC 20036. Tel: 800-227-5558; Tel: 202-872-4600; e-mail: eic@jce.acs.org; Web site: http://pubs.acs.org/jchemeduc
Erfasst von	ERIC (Education Resources Information Center), Washington, DC
Update	2020/1/01