JOURNRL OF
Chemical Education: Software Abstract: Volume IV B, Number 2 Mass Spec Simulator D. Bruce Armitage
Thiel College Greenville, PA 16125 Mass Spec Simulator is a simulation of a Varian EM-600 mass spectrometer(ca. 1979).I t shows the two main control panels of the instrument and a screen for displaying the mass spectrum. The user can adjust all of the commonly used controls, for example, spectrum amplitude, mass range, and starting mass. There is also a realistic simulation of sample introduction for both solid and liquid samples. All controls are operated using a mouse pointing device. The instrument responds realistically whether or not sample and operating conditions are appropriate. Actions that would cause incorrect operation are either not allowed with a n explanation or carried through with the result explained in i n information box. Mass spectra are derived from data files containinlr mass and intensity values from the literature. Files for up to 80 compounds (20 are provided) can be edited andior created
using a separate program (provided) or most word processors. The mass units and intensity values can be obtained from the displayed spectra using the mouse. Hard copies of the spectra can also be obtained using an IBM or Epson compatible printer. The simulation can be used (1)to teach instrumental analysis students the operation of the real instrument, 12, a s H novel way to pmvlde organic qual~tatwe analys~sstudents w t h mass spectra of unknown;. 13 to demonstrate the isotopic abundances of halogens, kc., and (4) to serve as a substitute if a mass spectrometer is not available.
N021N204 Equilibrium Experiment Teresa Anderson Curtln Physics &AstronomyDepartment 201 Phillips Hail, CB3255 University of North Carolina at Chapel Hill Chapel Hill, NC 27514
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Darryl Wahlstrom Huron High School Ann Arbor, MI 48109 James McCormlck University of Wisconsin-Madison Madison, WI 53706 NOz/N204 Equilibrium Experiment introduces the student to the use of computers to collect experimental data, analyze the data collected, and incorporate the results of the analysis into a laboratory report. As its name suggests, it focuses on a study of the chemical equilibrium that exists between gaseous dinitrogen tetroxide (Nz04)and gaswus nitrogen dioxide (NOz). Students measure the absorbance of a mixture of NO2 and N2O4 as a function of temperature between 25 and 100 "C. The data are obtained by interfaeing the game-control port of a n IBM microcomputer to a eolorimeter called a Blocktronic. Directions for building the Blocktronic a r e included in the documentation. The computer's game-control reading of the gas sample is converted to a n absorbance reading by utilizing calibration data from the Blocktronic. Once the absorbance of NOz a t the various temperatures is recorded. the values for the equilihnum constant, K,, can he determined at each of the temperatures. Lastly, the cquilibrium constant results are analyzed .graphically to arri;e a t values for the changes in enthalpy, AH, and entropy, AS.
About This Issue John W. Moore and Jon L. Holmes JCE: Software Editors..~~ University of Wisconsin-Madison Madison, WI 53706 Computer simulations of analytical instruments provide a n effective means of training students to use the instrument. The availability of these instruments to the beginning student is generally limited or nonexistent due to their cost and complexity. A simulation of the instrument used a s a pre-laboratory exercise familiarizes students with the instrument and allows them to make better use of the Volume 68 Number 9 September 1991
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