JCE Online Journal of Chemical EducationDivision of Chemical Education, American Chemical SocietyAmerican Chemical Society
 | Subscriptions  | Software Orders  | Support  | Contributors  | Advertisers  | 

JCE Print

JCE Digital Library

JCE Software

Only@JCE Online

About JCE


  Home > JCE Print > Journal of Chemical Education > Issues > 2007  > March  >
In the Laboratory
High-Resolution Vibration–Rotation Spectroscopy of CO2: Understanding the Boltzmann Distribution
Karen J. Castle
Department of Chemistry, Bucknell University, Lewisburg, PA 17837
Cover
March 2007
Vol. 84 No. 3
p. 459

Abstract
In this undergraduate physical chemistry laboratory experiment, students acquire a high-resolution infrared absorption spectrum of carbon dioxide and use their data to show that the rotational–vibrational state populations follow a Boltzmann distribution. Data are acquired with a mid-infrared laser source and infrared detector. Appropriate absorption peak assignments are made by comparison of the experimental spectrum with the high-resolution transmission molecular absorption (HITRAN) database. Integrated absorption peak areas are used as a measure of relative rotational–vibrational state populations. The effect of temperature on the population distribution is explored by sampling the absorption spectrum at several different temperatures, giving students the opportunity to observe the properties of a Boltzmann distribution.
Supplement
Instructions for the students and notes for the instructor are available.
*
Download
Contents
More Information
*
Citation
Castle, Karen J. J. Chem. Educ. 2007 84 459.
*
Keywords
Gases; Hands-On Learning / Manipulatives; IR Spectroscopy; Laboratory Instruction; Lasers; Physical Chemistry; Quantum Chemistry; Statistical Mechanics; Upper-Division Undergraduate
*
History
Created:
Last Updated:
2/1/2007
2/16/2007
 Caution! 
Experiments, laboratory exercises, lecture demonstrations, and other descriptions of the use of chemicals, apparatus, instruments, computers, and computer interfaces are presented in the Journal of Chemical Education as illustrative of new or improved ideas or concepts in chemistry instruction and are directed at qualified teachers. Although every effort is made to assure and encourage safe practices and safe use of chemicals, the Journal of Chemical Education cannot assume responsibility for uses made of its published materials. Many chemicals are hazardous. Precautions for the safe use of hazardous chemicals and directions for their proper disposal are described in the Material Safety Data Sheets and on the labels. We strongly urge all those planning to use materials from our pages to make choices and to develop procedures for laboratory and classroom safety in accordance with local needs and situations.
  Home > JCE Print > Journal of Chemical Education > Issues > 2007  > March  > Page 459


Subscriptions

JCE HS CLIC

Our Secondary School editors work hard to distill all the JCE materials to produce a fraction of particular interest to high school teachers. We call it CLIC.


Contributions Welcome
JCE welcomes your submission

Advertisers
In recent years we have worked hard to better match our advertisers with our readers. When shopping for chemistry education materials, visit our advertisers' WWW sites first.

Be An Ambassador
Take JCE along on your outreach missions. Copies of the Journal, guest access to JCE Online, our publications catalog, and more are available for your participants.