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  > September  >
Research: Science and Education
Unified Approximations: A New Approach for Monoprotic Weak Acid–Base Equilibria
Harry L. Pardue, Ihab N. Odeh, and Teweldemedhin M. Tesfai
Department of Chemistry, Purdue University, West Lafayette, IN 47907-1393
Cover
September 2004
Vol. 81 No. 9
p. 1367
Abstract
This article describes a new approach to approximate calculations for monoprotic acid–base equilibria in otherwise pure water. The new approach, identified herein as unified approximations, uses a simple decision criterion to select between situations that should be treated as deprotonation and protonation reactions. The remaining treatment takes account of changes in concentrations of conjugate acid–base pairs for all situations and ignores autoprotolysis only for situations for which the analytical concentration of either the conjugate acid or conjugate base will always be larger than zero. The net result is a process that leads to two similar quadratic equations that give approximation errors of 5% or less for a range of situations for which 10 different sets of decisions, simplifying assumptions, procedures, and mathematical relationships are needed using classical or graphical methods.
More Information
*  Citation
 Pardue, Harry L.; Odeh, Ihab N.; Tesfai, Teweldemedhin M. J. Chem. Educ. 2004 81 1367.
*  Keywords
 Acid–Base Chemistry; Analytical Chemistry; Equilibrium; General Chemistry; Teaching/Learning Theory/Practice
*  History
 Created:
Last Updated:		 July 28, 2004
August 13, 2004
<< Previous article Table of Contents Next Article >>
  Home > JCE Print > Journal of Chemical Education > Issues > 2004 > September > Page 1367


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's 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.