NotesFAQContact Us
Search Tips
Peer reviewed Peer reviewed
Direct linkDirect link
ERIC Number: EJ814868
Record Type: Journal
Publication Date: 2008-Nov
Pages: 3
Abstractor: As Provided
ISSN: ISSN-0021-9584
Gas Nonideality at One Atmosphere Revealed through Speed of Sound Measurements and Heat Capacity Determinations
Halpern, Arthur M.; Liu, Allen
Journal of Chemical Education, v85 n11 p1568-1570 Nov 2008
Using an easy-to-make cylindrical resonator, students can measure the speed of sound in a gas, u, with sufficiently high precision (by locating standing-wave Lissajous patterns on an oscilloscope) to observe real gas properties at one atmosphere and 300 K. For CO[subscript 2] and SF[subscript 6], u is found to be 268.83 and 135.25 m s[superscript -1], respectively, versus their ideal-gas (zero-pressure) values of 270.15 and 136.67 m s[superscript -1]. These differences arise from intermolecular interactions. It is shown that if the molar isobaric heat capacities, C[subscript p], m, are calculated from the one atmosphere u values assuming perfect gas behavior, significant errors are produced. For CO[subscript 2] and SF[subscript 6] these errors are 2.7% and 25%, respectively. Experimental C[subscript p], m values are compared with those obtained based on the equipartition theorem. (Contains 1 figure and 2 tables.)
Division of Chemical Education of the American Chemical Society. Subscription Department, P.O. Box 1267, Bellmawr, NJ 08099-1267. Tel: 800-691-9846; Tel: 856-931-5825; Fax: 856-931-4115; e-mail:; Web site:
Publication Type: Journal Articles; Reports - Evaluative
Education Level: Higher Education
Audience: N/A
Language: English
Sponsor: N/A
Authoring Institution: N/A