Analysis of the Vibrational Spectrum of a Linear Molecule©
Richard W. Schwenz
Department of Chemistry and Biochemistry
University of Northern Colorado
Greeley, CO 80639
United States
mail to: Richard.Schwenz@unco.edu

William F. Polik
Department of Chemistry
Hope College
Holland, MI 49423
United States

Sidney H. Young
**Sid Young died in 2004 after a long illness. He was a beloved teacher and a leader in the development and use of Mathcad as a tool to promote student learning in physical chemistry. A memorial to Dr. Young was established by the University of South Alabama ACS Student Affiliate, http://www.southalabama.edu/acs/memorial.html

This document provides a moderately interactive tutorial describing the analysis of vibrational frequencies obtained from the infrared spectrum of hydrogen chloride. The hcl.prn file contains sample data that was created using a standard spreadsheet program. The data file is simple ASCII text in columns. The Mathcad document treats the data by using non-linear curve fitting to obtain the spectroscopic parameters. Students are directed to another document to learn more details of the non-linear curve fitting procedure. For the typical student in a first course in physical chemistry the material contained here is sufficient. The importance of the approach presented here is that students are able to easily obtain the standard deviation for each of their spectroscopic constants. The document contains questions for students to answer all during the analysis. After practicing with the sample data, students may prepare the data they collected in the laboratory as decribed in the document and use the document to complete a data analysis very quickly. This frees up student time for thinking and reflecting on the concepts associated with vibrational spectroscopy. The document contains mastery exercises to challenge students and test their understanding of the material.
Editor's Commentary
Audiences: Upper-Division Undergraduate
Pedagogies: Computer-Based Learning
Domains: Laboratory Instruction, Physical Chemistry
Topics: IR Spectroscopy, Mathematics / Symbolic Mathematics, Quantum Chemistry, Spectroscopy
File NameDescriptionSoftware TypeSoftware Version
hcl.nb Mathematica Computational Document Mathematica
VibrationalSpectrum_mcd.pdf Read Only Document for Mathcad
VibrationalSpectrum_nb.pdf Read Only Document for Mathematica
hcl.txt JCE Data File for use with with Mathcad file.
VibrationalSpectrum.nb JCE Mathematica Computational Document Mathematica
VibrationalSpectrum.mcd JCE Mathcad Computational Document Mathcad
JCE JCE Subscribers only: name and password or institutional IP number access required.
Schwenz, R. W.; Polik, W. F.; Young, S. J. Chem. Educ. 2000 77 670.
Comments to: Richard.Schwenz@unco.edu
©Copyright 2004 Journal of Chemical Education