ERIC Number: EJ1196685
Record Type: Journal
Publication Date: 2018-Nov
Pages: 3
Abstractor: As Provided
ISBN: N/A
ISSN: ISSN-0021-9584
EISSN: N/A
The Gibbs Phase Rule: What Happens When Some Phases Lack Some Components?
Journal of Chemical Education, v95 n11 p2086-2088 Nov 2018
The derivation for the Gibbs phase rule, provided in physical chemistry text books, often assumes that all the components are present in all the phases coexisting at equilibrium. However, very often we have situations where all the phases at equilibrium do not have all the components, the binary eutectic system being a classic example. The melt (miscible solution of A and B) coexists with pure solid A and pure solid B at the eutectic point. The solid phases are one-component phases, whereas the system itself is binary. How does the phase rule, derived under the above mentioned assumption, apply to the eutectic point? Using a simple example, we demonstrate that all the components "need not" be present in all the phases to arrive at the phase rule.
Descriptors: Chemistry, Science Instruction, Scientific Concepts, Misconceptions, Undergraduate Study, College Science, Standards
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
Publication Type: Journal Articles; Reports - Descriptive
Education Level: Higher Education; Postsecondary Education
Audience: N/A
Language: English
Sponsor: N/A
Authoring Institution: N/A
Grant or Contract Numbers: N/A