Equilibrium

Articles

Back Burner: When Push Comes to Shove: Disturbing the Equilibrium
February 1985 (pp 14-15)

Author:  Derek Davenport
Chemistry Connections:
  Equilibrium, Biography/History
Description:
  Discusses Le Châtelier’s principle. Chronicles Le Châtelier’s work with equilibrium systems, focusing especially on the production of ammonia from hydrogen and atmospheric nitrogen—the process developed commercially by Fritz Haber (much to the chagrin of Le Châtelier, as noted in the article). Traces briefly the life of and the discoveries made by Le Châtelier. Good basic coverage of how Le Châtelier’s principle works—useful for the classroom. Includes a subsequent one-page article on a practical example of Le Châtelier’s principle, describing the effect of ambient temperature on the equilibrium involved in egg shell production in chickens. No Teacher’s Guide was produced for this early article.

What's so Equal about Equilibrium?
September 2005 (pp 11-13)

Author:  Michael Tinnesand
Chemistry Connections:
  Equilibrium, Reactions
Description:
  After defining equilibrium, the article uses the atmosphere as an application of equilibrium concepts. Compares similarities and differences in the term “equilibrium” in physics, chemistry, and everyday life. Defines and describes chemical equilibrium in detail, especially the dynamic nature of chemical equilibrium. Discusses why most reactions are not written as equilibrium reactions. Applies equilibrium to atmospheric conditions, focusing on ozone concentrations at low and higher elevations in the atmosphere. Good diagram of sources of ozone and equilibrium reactions occurring in those elevations. Mentions complexity of equilibrium systems on a global scale and the need for further studies, especially by scientific satellites in orbit around the Earth.

Demystifying Gross Stuff
October 2011 (pp 12-14)

Author:  Brian Rohrig
Chemistry Connections:
  Equilibrium, Acids/Bases, Organic/Biochemistry
Description:
  Relates three health issues very relevant to teenagers—acne, bad breath, and flatulence—to bacteria. Provides causes of zits and ways to avoid/minimize zits. Discusses amphiphilic nature of soaps, and the polar nature of water vs. the non-polarity of fats and oils. Discusses micelles containing sebum surrounded by soap molecules. Discusses bacterial waste as the cause of smelly breath. Describes the acid-base equilibrium chemistry involved with remineralizing tooth enamel using fluoridated mouthwashes (which not only kill bacteria, but also strengthen teeth). Discusses chemistry of gases produced in bacterial waste, both in bad breath and in flatulence. Describes flatulence as a natural biological process caused by chemical breakdown of cellulosic materials. Also briefly describes lactose intolerance.

Articles available on the ChemMatters DVD

Nitrogen From Fertilizers: Too Much of a Good Thing
April 2010 (pp 5–7)

Author: Beth Nolte
Chemistry Connections:
Equilibrium, Organic/Biochemistry, Reactions, Solids/Liquids/Gases
Description:
Describes the nitrogen cycle and the role of excessive use of nitrogen fertilizers in polluting the environment. The chemistry of nitrogen, ammonia, oxides of nitrogen and nitrates are emphasized. Suggests that changes in farming methods can ameliorate the environmental effects. Includes sidebars on organic farming and the Haber-Bosch method of producing ammonia.

Letting Off Steam
April 2009 (pp 4–7)

Author: Carolyn Ruth
Chemistry Connections:
Equilibrium, Reactions, Solids/Liquids/Gases, Solutions
Description:
Information on the mechanics of geyser and hot spring formations that include deep earth heating of water which dissolves various molten rock (magma) minerals (silicon dioxide, calcium carbonate) that is brought to the surface to form solidified deposits. Other chemicals in an eruption include mercury, arsenic, hydrogen sulfide and carbon dioxide. Last page includes two student activities: making a volcano with soap, baking soda and vinegar, and boiling water at various temperatures with a vacuum filtration flask and a faucet with a suction filtration attachment.

Unusual Sunken Treasure
December 2006 (pp 11–13)

Author: Tim Graham
Chemistry Connections:
Equilibrium, Organic/Biochemistry, Solids/Liquids/Gases, Solutions
Description:
Raising a Norwegian sunken ship (torpedo, 1916) full of champagne requires understanding of the gas laws—effect of temperature, pressure on dissolved carbon dioxide in champagne. Asides on fermentation, processing champagne, what produces the fine bubbles.

ChemMystery; Real or Fake? The James Ossuary Case
February 2006 (pp 8–10)

Author: Lois Fruen
Chemistry Connections:
Atomic Theory, Equilibrium, History/Biography, Nuclear, Organic/Biochemistry
Description:
Discusses methods used to authenticate antiquities, focusing on radiocarbon dating. The process and the background science are described. Other methods described: hardness and density testing, microscopic analysis of mineral composition, mass spectrometry to measure O-18 to O-16 isotope ratios. Scientists reported the artifacts were fake, but then further research by other scientists refuted the fakery claims. The question remains unanswered. Chemistry centers on isotopic composition and presence of carbon dioxide in groundwater dissolving calcite (equilibrium equations provided).

The Amazing Drinking Bird!
October 2005 (pp 10–11)

Author: Brian Rohrig
Chemistry Connections:
Bonding, Equilibrium, Solids/Liquids/Gases, Thermochemistry
Description:
Describes what a drinking bird is and how it works. Explains the science behind the bird’s actions: evaporation of water cooling the top glass bulb, which lowers vapor pressure; greater vapor pressure at the bottom forces liquid up the tube until bird gets top-heavy and tips; liquid empties from tube, allowing pressure in two bulbs to equalize; process begins anew. Sidebar provides 5 additional experiments (extensions) to try with drinking birds.

Whose Air Is It Anyway?
October 2003 (pp 6–8)

Author: Jeannie Allen
Chemistry Connections:
Equilibrium, Reactions, Solids/Liquids/Gases, Sustainability
Description:
Describes composition of atmosphere—chemical, biological and circulation throughout the world. Ozone issue studied through satellites. Student experiment tracks atmospheric transport of fungal spores through smoke.

Alien Atmospheres: There’s No Place Like Home
October 2003 (pp 9–11)

Author: Frank Cardulla
Chemistry Connections:
Equilibrium, Reactions, Solids/Liquids/Gases
Description:
Compares atmospheres of Earth, Venus and Mars. Chart summarizes chemical and physical characteristics of the three planets. Explains physical characteristics (temperature, surface erosion) because of different chemical compositions of the three atmospheres.

Activity: Cloud in a Bottle
October 2003 (pp 16–17)

Author: Bob Becker
Chemistry Connections:
Equilibrium, Solids/Liquids/Gases, Thermochemistry
Description:
This activity description details how to create clouds in a soda bottle through phase changes and the factors responsible for the creation—condensation of water vapor through pressure changes that create a temperature change.

Life in a Greenhouse
October 2003 (pp 18–21)

Author: Helen Herlocker
Chemistry Connections:
Acids/Bases, Equilibrium, Reactions, Sustainability
Description:
Explains the greenhouse effect; role of atmospheric chemicals absorbing infrared radiation. Carbon dioxide, water vapor, methane, nitrous oxide, ozone, dichlorodifluoromethane, trichlorofluoromethane listed with their relative effectiveness in absorbing infrared. Diagrams.

Beefing Up Atmospheric Models
October 2003 (pp 25–28)

Author: Kevin McCue
Chemistry Connections:
Equilibrium, Reactions, Solids/Liquids/Gases
Description:
Use of supercomputers to develop mathematical models of the atmosphere and weather patterns to forecast weather. Need data input from a variety of atmospheric parameters including emissions, deposition, transport, and chemical interactions of various gaseous components of the atmosphere. Short-term and long-term predictions of changing weather conditions have different limitations.