JCE Online Journal of Chemical Education
 | Subscriptions  | Software Orders  | Support  | Contributors  | Advertisers  | 

JCE Print
   Current Issue
 Previous Issues
 Supplements
 Search JCE Index

JCE Digital Library
   JCE DLib Catalog
   ChemInfo
 Data-Driven Exercises
 DigiDemos
 Featured Molecules
 LivTexts
 LrnCom
 QBank
 SymMath
 WebWare

JCE Software
   Latest Releases
 Software & Video
 Downloads
 Support

Only@JCE Online
   JCE Online Store
 JCE HS CLIC
 JCE Discussion Forums
   Biographical Snapshots
 ChemEd Resource Shelf
 Hal's Picks
 Project Chemlab
 Reviewed WWW Sites
 "Web-Ed" Articles

About JCE
   Features
 Publications
 Operations
 Outreach
 Contact Us



  Home > JCE Print > Journal of Chemical Education > Issues > 2004  > December  >
In the Laboratory
A Laser-Pointer-Based Spectrometer for Endpoint Detection of EDTA Titrations
Christopher E. Dahm and James W. Hall
Department of Chemistry and Physics, Wingate University, Wingate, NC 28174

Brian E. Mattioni
Department of Chemistry, The Pennsylvania State University, University Park, PA 16802

Cover
December 2004
Vol. 81 No. 12
p. 1787
Abstract
A simple laser-pointer-based spectrometer has been developed for endpoint detection of EDTA titrations of magnesium and calcium. This spectrometer was built to decrease the uncertainty in determining the endpoint of titrations performed with a Calmagite indicator. With a photoresistor as the detector, and with the aid of a voltage-divider circuit, the quantity of light being absorbed can be followed with a simple pH–voltmeter. Students determine the endpoint by graphing the data and applying simple mathematics. Beer–Lambert studies with the spectrometer also show excellent agreement for a given set of solutions.
Supplement
Instructions for the students and notes for the instructor are available.
*  Contents JCE2004p1787W.doc (Microsoft Word)
*  Download
JCE2004p1787W.pdf

JCE2004p1787W.zip

JCE2004p1787W.sit
More Information
*  Citation
 Dahm, Christopher E.; Hall, James W.; Mattioni, Brian E. J. Chem. Educ. 2004 81 1787.
*  Keywords
 Analytical Chemistry; Calcium; Dyes; General Chemistry; Laboratory Equipment / Apparatus; Laboratory Instruction; Lasers / Laser Spectroscopy; Magnesium; Titration / Titrimetry
*  History
 Created:
Last Updated:		 November 1, 2004
November 9, 2004
<< Previous Article Table of Contents Next Article >>
  Home > JCE Print > Journal of Chemical Education > Issues > 2004  > December  > Page 1787


Subscriptions
 Subscription Info
 Order Forms

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.
 JCE HS CLIC

Contributions Welcome
JCE welcomes your submission
 Contributors' Corner

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.
 Recent Advertisers

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.
 Outreach with JCE

Comments to
jceonline@chem.wisc.edu		 Copyright © Division of Chemical Education, Inc., American Chemical Society.
All rights reserved.