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



  Home > JCE Print > Journal of Chemical Education > Issues > 1999  > February  >
In the Classroom
Tested Demonstrations
The Ammonia Smoke Fountain: An Interesting Thermodynamic Adventure
submitted by: M. Dale Alexander
Department of Chemistry and Biochemistry, New Mexico State University, Las Cruces, NM 88003

checked by: Daniel T. Haworth
Department of Chemistry, Marquette University, Milwaukee, WI 53201

Cover
February 1999
Vol. 76 No. 2
p. 210
Abstract
The ammonia smoke fountain demonstration utilizes a modification of the apparatus used in the standard ammonia fountain. The modification allows for the introduction of hydrogen chloride gas into a flask of ammonia rather than water. The demonstration is initiated in the same way as the ammonia fountain, however. A small amount of water is introduced into a flask containing ammonia, and the pressure decreases as in the ammonia fountain. This results in hydrogen chloride being drawn into the flask instead of water, and a familiar reaction occurs, the combination of ammonia and hydrogen chloride to form ammonium chloride smoke. The pressure drops owing to the conversion of ammonia gas to solid ammonium chloride by the reaction with hydrogen chloride, and more hydrogen chloride gas is drawn into the reaction flask. The flow rate of hydrogen chloride gas into the flask in the smoke fountain is not constant, but periodic; that is, the smoke puffs from the end of the tube. This unexpected behavior elicits an interesting thermodynamic explanation.
More Information
*  Citation
 Alexander, M. Dale. J. Chem. Educ. 1999 76 210.
*  Keywords
 Demonstrations; Physical Chemistry; AcidBase Chemistry; Gases; Thermodynamics
*  History
 Created:
Last Updated:		 June 15, 1999
June 22, 2005
<< Previous Article Table of Contents Next Article >>
  Home > JCE Print > Journal of Chemical Education > Issues > 1999 > February > Page 210



Chemistry Teacher Connection

The "Chemistry Teacher Connection" (CTC) is especially for high school chemistry teachers. For only $40/year, it offers an online-only subscription to CLIC along with membership in the Division of Chemical Education, normally $65/year. CTC subscribers receive access to all articles and supplements from 1996 through the current issue.
More About CTC
Order the Chemistry Teacher Connection

C&EN CLICs

Through special arrangement with the ACS, JCE High School CLIC is now able to provide subscribers with online access to Chemical & Engineering News articles that have been selected specifically for secondary science instructors and their students. 
 C&EN CLICs

JCE Collections Available
Occasionally, collections of JCE back issues become available for donation to individual teachers, schools, or libraries. JCE matches collections with interested recipients. Recipients pay shipping costs or pick up the collection.
 List of available collections

Contributions Welcome
JCE welcomes your submission
 Contributors's Corner

Subscriptions
 Subscription Info
 Order Forms

Fishing for New Ideas
Always in the
process of
improving, CLIC
welcomes ideas and comments.

Email Us

NSF logoDivCHEDACS ACS PubsFor journals in other fields of chemistry visit ACS Publications.
Comments to
jceonline@chem.wisc.edu		 Copyright © 2008 Division of Chemical Education, Inc., American Chemical Society.
All rights reserved.		  Terms | Privacy