Chemical Reactions

Free Articles

The Great Hartford Circus Fire
February 2005 (pp 4-7)

Author:  Brendan Rimetz
Chemistry Connections:
  Bonding, Biography/History, Organic/Biochemistry, Reactions, Solutions
Description:
  Tells the history of a fire that destroyed the Ringling Brothers and Barnum & Bailey Circus “big top” tent in July, 1944 and killed or injured almost 900 people. Focuses on waterproofing agent, composed of paraffin wax and gasoline. Discusses polarity of water, and non-polarity of gasoline and paraffin, and why the latter two chemicals were used to waterproof the tent canvas, and describes the synergistic (in this case, synergistically BAD) effects of using the two organic substances together, and why firefighters using water to put out the fire were unsuccessful. Discusses second waterproofing substance, with little known about its composition. Sidebar tells a survivor’s story. Second sidebar discusses colloidal dispersions to dissolve polar and non-polar substances together.

Sugar: An Unusual Explosive
December 2010 (pp 5-7)

Author:  Michael Tinnesand
Chemistry Connections:
  Reactions
Description: 
Describes explosion in a sugar refinery and causes of the explosion. Explains requirements for explosion: rapid reaction in an enclosed space, and relates to the sugar refinery explosion. Compares at the molecular level the normal combustion of sugar (marshmallow) to a sugar dust explosion, including rate of reaction related to surface area. Includes other types of dust explosions: dust from coal, flour, metals, plastics and wood are all susceptible to exploding under the right conditions. Examines role of the U.S. Chemical Safety and Hazard Investigation Board (CSB) and the Occupational Safety and Health Administration (OSHA) in investigating these incidents.

The Ozone Layer: Our Global Sunscreen
April 2013 (pp 12-14)

Author:  Mike Carlowicz
Chemistry Connections:
  Reactions
Description:
  Discusses computer simulations that experimented (virtually) with Earth’s atmosphere by continuing to add ozone-destroying chemicals. Provides history of chlorofluorocarbons (CFCs)—their discovery, production, uses, and eventually-recognized hazards. Explains chemistry of CFCs and ozone destruction in upper atmosphere, showing role of chlorine in reactions that continuously destroy ozone. Describes methods of detection of ozone hole in atmosphere using data collected by weather balloons, airplanes and satellites, utilizing spectrometers or photometers. Discusses 1987 Montreal Protocol, United Nations international agreement that banned ozone-depleting substances such as CFCs; scientists are hopeful, although its effects are not yet known. Sidebar discusses good ozone vs. bad ozone—ground-level vs. stratospheric ozone.

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.

Green Gasoline: Fuel from Plants
February 2010 (pp 13–15)

Author: Michael Schirber
Chemistry Connections:
Bonding, Organic/Biochemistry, Reactions, Thermochemistry
Description:
Describes how molecules, like cellulose, found in plants like switchgrass and plant “leftovers” like corn stalks, can be made into gasoline. Uses lots of graphics to explain the use of zeolite catalysts in the process of stripping oxygen atoms from carbohydrate molecules to make hydrocarbon molecules that, in turn, make gasoline. Distinguishes green gasoline from biofuels like ethanol. Describes benefits of green gasoline.

Hollywood’s Special Effects—How Did They Do That?
December 2009 (pp 5–8)

Author: Diana Lutz
Chemistry Connections:
Bonding, Organic/Biochemistry, Reactions, Solids/Liquids/Gases, Thermochemistry
Description:
Describes how various special effects are created for movies, including fake snow, fake skin, fire and explosions. Some chemistry is detailed to explain how the materials are produced.

Space Food
December 2009 (pp 11–13)

Author: Diana Lutz
Chemistry Connections:
Reactions, Solids/Liquids/Gases
Description:
Various techniques for preserving food for astronauts detailed including freeze-drying, thermostabilizing and irradiating. Goal to eliminate bacteria and water. Water for rehydration from fuel cell chemical reaction.

Where Do Chemical Elements Come From?
October 2009 (pp 6–8)

Author: Carolyn Ruth
Chemistry Connections:
Atomic theory, Nuclear, Periodicity, Reactions
Description:
Describes the various processes for producing the various elements in stars of various types. Fusion, fission and “r” reactions detailed. Spectroscopy used to identify the elements in stars and gaseous clouds.

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.

Ancient Soil Chemists of the Amazon
February 2009 (pp 7–9)

Author: Mark Michalovic
Chemistry Connections:
Reactions, Solutions, Sustainability
Description:
Unraveling an ancient mystery as to how rainforest soils could be used for cultivation by Amazonians 500 years ago. Natives altered the soil with charcoal (biochar) to create negatively charged particles (carboxylates) that attract important nutritional positive ions (calcium, potassium) that plants need. Normal rainforest soil high in positively charged clay particles from aluminum and iron that do not attract needed calcium and potassium.

Bringing Chemistry to the Kitchen
February 2009 (pp 10–12)

Author: Patrice Pages
Chemistry Connections:
Organic/Biochemistry, Reactions, Solids/Liquids/Gases, Solutions
Description:
Experimental cooking based on some understanding of chemistry and physics but primarily experimental using new physical forms of ingredients in the mix. Influence of color on taste perception studied; good taste influences amount eaten (savoring means less eaten)

Glowing Proteins with Promising Biological and Medical Applications
December 2008 (pp 12–14)

Author: Linda Zajac
Chemistry Connections:
History/Biography, Organic/Biochemistry, Reactions
Description:
Discusses research done to discover why crystal jellyfish glow in the dark, which led to discovery of green fluorescent protein (GFP, for short). Describes how GFP genes can be inserted into DNA of other cells that can then act as tracers as they travel throughout the body. Describes the uses of other colors of fluorescent proteins that have been discovered, including: tracking viruses in plant diseases, helping to cure brain diseases, and cancer therapy studies. Might be used in class in discussion of light emission and absorption and energy and wavelength of light.

The Olympic Flame: Chemistry Held High
October 2008 (pp 4–5)

Author: Brian Rohrig
Chemistry Connections:
Organic/Biochemistry, Reactions, Thermochemistry
Description:
Describes the history of the Olympic torch, and its 135-day relay trip to Beijing for the 2008 Olympics, which included an underwater portion and a trip up Mt. Everest. Then discusses the chemistry of the torch itself, including its composition and the many different fuels used in the torch over the years. Chemistry includes equations for combustion of propane and ammonium perchlorate (for the underwater part of the trip).

The Quest for a Clean Drink
April 2008 (pp 4–6)

Author: Christen Brownlee
Chemistry Connections:
Bonding, Metals/Nonmetals, Reactions, Solutions, Sustainability
Description:
Tells of the problems in India and Bangladesh of obtaining clean drinking water, starting with contamination of surface water, followed by arsenic contamination of groundwater. Then discusses three different practical methods of purifying the water to remove the arsenic, all of which are being used successfully in these countries. The chemistry, including equations of the processes is illustrated.

Sniffing Landmines
April 2008 (pp 7–9)

Author: Sarah Vos
Chemistry Connections:
Organic/Biochemistry, Reactions, Thermochemistry
Description:
Discusses the use of trained dogs to sniff out landmines, and the need for both the dogs and handlers to be well trained. Says TNT (trinitrotoluene), the explosive of choice for landmines, can release DNT (dinitrotoluene) vapors, which dogs smell. Compares efficacy of sniffing dogs to metal detectors. Also covers research being done by military and academic groups to produce detectors that work the same way dogs’ noses do. Formulas for TNT and DNT, and equation for detonation of TNT are given.

ChemSumer: Sticky Situation: The Wonders of Glue
December 2006 (pp 8–10)

Author: Linda Shiber
Chemistry Connections:
Bonding, Organic/Biochemistry, Reactions, Solids/Liquids/Gases
Description:
Glues produced “biologically” by animals as well as chemical mixes from human experimentation are explained in chemical terms. Even cilia of geckos utilize induced dipoles (London dispersion) between cilia and surfaces for attachment.

ChemHistory: The Race for Iodine
December 2006 (pp 18–19)

Author: Mark Michalovic
Chemistry Connections:
History/Biography, Periodicity, Reactions, Solutions
Description:
Relates the history behind two competitive chemical pioneers, Davy and Gay-Lussac, their simultaneous investigation to determine the chemical composition of a purple substance isolated from seaweed. Both chemists determine it is the element iodine, not a chlorine compound.

Glass: More Than Meets the Eye
October 2006 (pp 4–8)

Author: Brian Rohrig
Chemistry Connections:
Reactions, Solids/Liquids/Gases, Solutions
Description:
Details the physical and chemical tests used at crime scenes for analyzing glass. Includes density, chemical composition, chemical changes, and type of fracture. Two student activities are included: Disappearing glass with glycerol and water, and Forensic Identification of Glass, with isopropanol and water.

Sick Buildings—Air Pollution Comes Home
October 2006 (pp 12–14)

Author: Michelle Laliberte
Chemistry Connections:
Bonding, Nuclear, Organic/Biochemistry, Reactions, Sustainability
Description:
Homes can have multiple sources of pollution: biological (mold, dust mites), chemical (formaldehyde, radon, carbon monoxide). Chemistry of CO poisoning and formaldehyde resin formation shown.

Material Safety Data Sheets: Passport to Safety?
October 2006 (pp 18–19)

Author: Michael Tinnesand
Chemistry Connections:
Reactions
Description:
Describes the rationale by OSHA to require descriptions of chemicals and their safe usage in commercial settings and academic labs.

GreenChem: Biomimicry—Where Chemistry Lessons Come Naturally
April 2006 (pp 15–17)

Author: Kathryn Parent and Jennifer Young
Chemistry Connections:
Organic/Biochemistry, Reactions
Description:
This green chemistry article explains biomimicry—studying natural chemical processes and trying to duplicate them for technological purposes. Cites and explains examples—super-strong silk produced from amino acids by the golden orb weaver spider, the irritant made from hydroquinone and hydrogen peroxide and emitted by the bombardier beetle and the strong water-resistant glue produced by mussels.

Nanomotors
April 2006 (pp 18–19)

Author: Anne Rosenthal
Chemistry Connections:
Organic/Biochemistry, Reactions
Description:
Describes and explains the structure and mechanism of the biological nanomotors that propel bacterial flagella. Compares electrical and biological motors. Emphasizes the role of proton diffusion in the cell as the driving force for the bio-motors. Gives examples of synthetic nanomotors made from carbon nanotubes, and catalytic nanomotors made of platinum and gold and propelled by the decomposition of hydrogen peroxide.

Flaking Away
February 2006 (pp 17–19)

Author: Christen Brownlee
Chemistry Connections:
Metals/Nonmetals, Reactions, Solutions, Sustainability
Description:
Talks about the demise of older cars due to rusting, focusing on the role of electrons in this chemical reaction, oxidation-reduction. Discusses how different regions of the same metal piece can act as anodes and cathodes simultaneously, and how water as a solvent for ions on the surface is the connector between these two areas of positive and negative charge that allows redox to occur. Differences in rusting rates in different geographical regions of the country are attributed to the presence of salt, either from ocean spray in coastal areas, or from salting of roads in colder regions of the country. Also discussed: reversing the rusting process (not practical), other objects that rust, the cost of rust, and paints to prevent corrosion. Chemical equations for rusting are provided.

Lab on a Stick
October, 2004 (pp 9–12)

Author: Christen Brownlee
Chemistry Connections:
Acids/Bases, History/Biography, Organic/Biochemistry, Reactions, Solutions
Description:
Recounts attempts to find an easy-to-use colorimetric urine test for diabetes. Includes early chemical testing, from the use of copper (II) sulfate-sodium hydroxide-ammonia reagent, to the advance made by Walter Compton who combined the reagents into tablet form (called Clinitest), to the modification made by Helen and Al Free which was a tablet that tested urine for ketone bodies. Describes the paper strip test, also developed by the Frees, which uses glucose enzymes to test for sugar in urine. Eventually the paper strip developed by the Frees contained ten tests in a single strip. The test strips are called Multistix-10SG. Article includes photos of the test strips. An interview with Helen Free follows the article.

ChemHistory: Cleopatra's Perfume Factory and Day Spa
October 2004 (pp 13–15)

Author: Lois Fruen
Chemistry Connections:
Reactions, Solids/Liquids/Gases, Solutions
Description:
Describes Cleopatra’s contributions to skin care treatments, which she developed at the spa and perfume factory given to her by Mark Anthony. The article notes the chemicals that were used in these ancient treatments and describes how modern chemistry has confirmed their composition by modern analysis. A sampling of ancient substances includes tar or pitch, salt, moringa oil, horseradish oil, olive oil and henna. The article lists modern chemicals that were present in some of Cleo’s formulations—indoles, amines, copper (II) carbonate, lead (II) sulfide and lead carbonate. The latter two compounds do not occur naturally, and the article describes the way in which the Egyptians synthesized them.

MysteryMatters: When Good Science Goes Bad!
October 2004 (pp 16–18)

Author: Tim Graham
Chemistry Connections:
Organic/Biochemistry, Reactions
Description:
Reviews the evidence used to convict a mother of poisoning her son with ethylene glycol and points out how analytical testing can yield inaccurate results. Also focuses on chemical reactions in the human body that can be used to identify chemicals present in the body. Explains the working of the gas chromatograph-mass spectrometer. A good forensic chemistry article.

Chemsumer: The Aspirin Effect: Pain Relief and More
February 2004 (pp 7–9)

Author: Doris Kimbrough
Chemistry Connections:
History/Biography, Organic/Biochemistry, Reactions
Description:
Relates the chemistry of non-steroidal anti-inflammatory drugs (NSAIDS) to the chemistry of prostaglandins and their role in the body’s pain producers. Explains that prostaglandins are lipids with a five-carbon ring as part of their structure. Also explains that prostaglandins are derived from arachidonic acid in a series of chemical reactions the article calls the arachidonic acid pathway. Recounts the history of aspirin and other NSAIDS like ibuprofen, acetaminophen and naproxen and explains that these compounds relieve pain in the body by inhibiting the production of prostaglandins.

Vanilla! It’s Everywhere!
December 2003 (pp 4–6)

Author: Gail Haines
Chemistry Connections:
Nuclear, Organic/Biochemistry, Reactions
Description:
Describes historical origins of the most widely used flavoring, vanilla, sources of natural and methods to synthesize vanillin, chemical methods of analysis (authenticate natural vs. synthetic). Side bar describes most sensitive test using isotopic ratios of carbon to detect substitution of synthetic vanillin for natural.

MysteryMatters: Scanning Electron Microscopy Solves a Mystery!
December 2003 (pp 17–19)

Author: Tim Graham
Chemistry Connections:
Atomic Theory, Reactions
Description:
Use of scattering electron microscopy (SEM) to analyze chemical composition of defective car paint job. Diagrammatic scheme shows basics of SEM operation, results of paint analysis, and answers to the cause of defective paint.

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.

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.

Chemistry in the Sunlight
October 2003 (pp 22–24)

Author: Jeannie Allen
Chemistry Connections:
Organic/Biochemistry, Reactions, Solids/Liquids/Gases, Thermochemistry
Description:
Positive and negative effects of ozone in our atmosphere—blocking UV radiation, negatively affecting biological tissue. Sources of ozone—volcanoes, burning fossil fuels. Additional “pollutants” (volatile organic compounds, VOC, and nitrogen oxides, NOx) and their effects are described.

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.

Nobel Prize Winner Sherwood Rowland: A Conversation
October 2003 (pp 29–30)

Author: David Harwell
Chemistry Connections:
History/Biography, Reactions, Sustainability
Description:
An interview with Nobel Prize-winning chemist who in the 1970’s, along with Mario Moline, studied the chlorofluorocarbons (CFCs) and their role in destroying the ozone layer in the stratosphere where the ozone normally reduces the amount of harmful UV light reaching the earth’s surface. Important points in the interview include his life in high school at the age of 12, the importance of playing sports, how he got into the study of the atmosphere, the effect on his life as a Nobel Prize winner, the effects on the atmosphere by banning the CFCs.

Measuring Ground-Level Ozone
September 2002 (pp 8–9)

Author: Frank Cardulla
Chemistry Connections:
Reactions
Description:
An activity for students to measure ozone levels, using Schönbein paper. One part describes reasons for testing for ozone, one part describes the procedure to make Schönbein paper, and the third part describes the test method and the analysis of the data obtained from the test. The chemical equations for the reaction of the ozone with the KI/starch test paper are shown.

Ozone—Molecule With a Split Personality
September 2001 (pp 7–9)

Author: Doris Kimbrough
Chemistry Connections:
Reactions, Solids/Liquid/Gases
Description:
Profiles ozone and compares its role in the stratosphere as an UV radiation absorber and in the troposphere as a pollutant. Stresses the fact that ozone is ozone, but its effects depend on where it is found in the atmosphere. Explains the chemistry of ozone formation. Details the impact of stratospheric ozone depletion on human health and plant and animal life.