|
|
| Home > JCE Print > Journal of Chemical Education > Issues >
1997
>
August
> |
|
In the Laboratory
|
|
|
|
Convection in a Continuously Stratified Fluid
|
Richard M. Heavers
Department of Chemistry and Physics, Roger Williams University, One Old Ferry Road, Bristol, RI 02809-2921
|
|
August 1997
Vol. 74 No. 8
p. 965
|
|
|
|
|
|
|
| Abstract |
|
This paper begins by commemorating Count Rumford's observations of convection in 1797. Rumford investigated the effects of stewed apples, eiderdown, and other fibrous materials on retarding vertical circulation in liquids. In contrast to Count Rumford's historic experiments, the present paper describes a simple, visually instructive, physical chemistry experiment for demonstrating how a mathematical model can be applied to free convection in a vertically stratified salt solution. In the first part of the experiment, a linear salt concentration profile is created in a beaker of water at room temperature. The salt concentration (and density) is greatest at the bottom of the liquid. When the beaker containing the salt solution is then heated on a hot plate, a well defined convecting bottom layer forms almost immediately. The measured rate of growth in thickness of this convecting layer is compared to that predicted from a model based on density differences. The temperature of the liquid above the bottom convecting layer remains close to its initial value, illustrating that heat from the hot plate is confined to the bottom layer by the salt (density) stratification.
|
|
| More Information |
 Citation |
Heavers, Richard M. J. Chem. Educ. 1997 74 965.
|
Keywords |
Demonstrations, History/Philosophy, Laboratory Instruction, Laboratory Equipment/Apparatus, Liquids
|
History |
Created:
Last Updated: |
July 28, 1999
June 23, 2005
|
|
|
|
|
|
| Home > JCE Print > Journal of Chemical Education > Issues >
1997
>
August
> Page
965
|
|
|
| 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. |
|
