The rapid compression or expansion of a gas in a plastic syringe is a poor approximation of an adiabatic process. Heat exchange with the walls of the syringe brings the gas to equilibrium in an amount of time that is not significantly greater than the length of the compression or expansion itself. Despite this limitation, it is still possible to measure the pressure changes during a rapid change in volume and calculate an approximation of the pressures for an adiabatic process. From these values the specific heat ratio of the gas can be calculated.
REFERENCES
1.
Model CI‐6532A for the Science Workshop interface in the 2008 PASCO Science & Engineering catalog; http://www.pasco.com.
2.
Model GPS‐BTA for LabPro and LabQuest interfaces in the Vernier catalog; http://www.vernier.com.
3.
See
David P.
Jackson
and Priscilla W.
Laws
, “Syringe thermodynamics: The many uses of a glass syringe
,” Am. J. Phys.
74
(2
), 94
–101
(Feb. 2006
) for an excellent list of experiments using syringes.4.
C. J. Overbeck, R. R. Palmer, and Marsh W. White, “Clement and Desormes' Experiment,” Selective Experiments In Physics (Sargent‐Welch Scientific Co., No. 71990‐371, 2003); available at http://www.sargentwelch.com/info.asp?ii=504.
5.
Michael J.
Moloney
and Albert P.
McGarvey
, “A simplified adiabatic compression apparatus
,” Phys. Teach.
45
, 452
–453
(Oct. 2007
).6.
J.
Mottmann
, “Laboratory experiment for the ratio of specific heats of air
,” Am. J. Phys.
63
, 259
–260
(March 1995
).7.
William W.
McNairy
, “Isothermal and adiabatic measurements
,”Phys. Teach.
34
, 178
–180
(March 1996
) reports 1.345.8.
Michael J.
Moloney
and Albert P.
McGarvey
, “A simplified adiabatic compression apparatus
,” Phys. Teach.
45
, 452
–453
(Oct. 2007
).reports 1.35.9.
J. D. Wright “Gas Property Equations for the NIST Fluid Flow Group Gas Flow Measurement Calibration Services” (NIST, Gaithersburg, MD, 2004); available online at http://www.cstl.nist.gov/div836/836.01/Publications.html.
10.
Dennis E.
Krause
and Walter J.
Keeley
, “Determining the heat capacity ratio of air from ‘almost adiabatic’ compressions
,” Phys. Teach.
42
, 481
–483
(Nov. 2004
).
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