Using News Media To Teach Chemical Principles Richard S. Myers Delta State University, Cleveland, MS 38733
News items pertaining to chemical science often attract our attention. Since they are often written by people with a limited knowledge of chemistry, they may contain errors. Chemists have an obligation to society to see that such events are accurately related to the general public and that confusion is minimized. It is the responsibility of teachers to see that students recognize such errors and relate a correct interpretation of the event. This is especially important for students in chemistry courses for nonscientists. Such erroneous reports maybe used to teach students the correct description of newsworthy events involving chemical principles. The "Newscripts" column in Chemical and Engineering News (K. M. Reese, Ed.) often cites such cases which contain errors or confusion involving chemical princinles. Below are portions of some news accounts wluch involve chemistrv Thev reoresent u mllection from the past several years of %ew&i&". Students are given the &signment of studying these reports and pointing out any errors. For each error, they write a brief description of the problem. There was a n account in a Florida newspaper describing a spill of hydrochloric acid from a ruptured tank at a water processing plant. Local officials "were concerned that the acid might mix with sodium hydroxide-austic soda-in a neighboring tank and form a toxic gas". As a precaution, several thousand people, including students a t four schools, were evacuated, and two highways were closed. A service company cleaned up the spill, and no injuries were reported. In a maeazine for veeetarians a reader asked for "the safest, most effective method for removing pesticide residue fromfreshfruits and vegetables without leaving a soap taste and without resortingto expensive commerc&l products". The magazine replied, in part, "Obtain an ounce of pure hydrochloric acid from a drugstore.... Dissolve the powder in three quarts of water. The solution can be saved and used many times. Place fruits and vegetables in the solution for five minutes, then remove and rinse well with pure water." This report was in a newspaper story about air bags in cars. "When the sensors detect a crash, their electronic signals prompt the ignition of sodium azide which rapidly turns into clean burning nitrogen gas." A tanker truck loaded with compressed nitrogen overturned in a town. In a reoort of the incident officials said, "There is no danger of explosion at this time." From a family gardening book: "inorganic fertilizers are chemical compounds that release the basic elements, nitrogen, phosphorus, and potassium, when mixed with the soil and watered. In their pure states these elements are not usable-nitrogen is an explosive gas." A Philadelphia newspaper reported a n explosion in a chemistry laboratory of a university. ...an explosion yesterday resulted from an experiment...in the campus laboratory. A university officialsaid that two men (eraduate students) were workinp with phosohoric acid, a &emical which explodes in contad;iith ai;. A television station stated in a report of a fire that "...sulfuric acid caught fire and burned".
A barge with a cargo of sulfuric acid capsized. "About 80% of the cargo was sulfuric acid which can produce a poison gas when mixed with water." Areport described the battery compartment of a submarine. This compartment contains the elements of a potential disaster. Should salt water somehow force its way into this area and come in contact with sulfuric acid in the batteries, deadly chlorine gas would immediately be generated, filling the interior of the submarine with lethal and explosive fumes. An advertisement on a radio station stated that "aU suears are exactlv alike." a television program i t was stated that iron oxide was inhaled by a construction worker who sufferedfrom emphy-
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A tank car plunged into a river and spilled its load. "The contents of the car was kaolin, a liquid substance." A mystery novel described "...the metallic residue ...dissolved in water and then precipitated by adding silver nitrate. That was a test for chlorates." Under the headlines, "Train Loaded with Toxic Acid Derails," the load was described as "ammonia and acetone". A newspaper in Fort Myers, FL, reported on a heavy fog that closed the harbor. A government meteorologist explained, "Fog is saturated air. As the air cools, the water molecules get bigger and bigger until they become visible." In a n article entitled "How to Avoid Afternoon Slurno." one of the suggestions was to "drink carbonated water. The oxveen in the bubbles eets into vonr bloodstream." " A newspaper in Los Angeles reported an interview with an expert on care of the teeth. The expert recommended buying small tubes of toothpaste because, "If you buy the large economy size tube, much of the fluoride is lost within two weeks...because fluoride is a volatile gas." A news report described the wreck of a train carrying "sodium carbonate and sodium bicarbonate, components of notash. used to make fertilizer and soao". ~---, - a~mineral -~~ From Tampa, FL, there was a report on a microorganism that can degrade nitroglycerin and is being tested for use on TNT. The scientists involved think microorganisms may offer an economical way to clean explosive storage sites. One is quoted as saying, "Eventually, we want to apply our knowledge of explbsives to similar compounds such as nuclear wastes." Containers of ammonia, bleach, and hydrochloric acid fell from a store cabinet in Massachusetts. The incident, was termed"achemical spill", that didnotbecome "deadly". The latter was due to Yuck", a consultant explained. "If i t was more in acid [sic] it would have caused lung cancer.... Ifthe ammonia had been greater it could suffocate you." A newspaper in Las Vegas, NM, reported an accident involving "granular bromine". From a maker of harps, 'We can only use a natural glue, because it won't change texture or become instable over the years. Chemicals will." From a North Carolina newsoaoer. . . . "Filline a cuoboard and bathroom with trnvironmenrally friendly'produ&scan he satisfvina. but it can also be costlv'h~o iars ofchemicnlfree shoe po%sh can run $13.95." A Durham, NC, ad for water crystals claimed "when mixed with potting or garden soil ... [they] will absorb up
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to 500 times their weight in water" and "will last 5 to 10 years before breaking down to nitrogen, COz, and water." The cost is just under $24 per pound. An advertisement for a "fuel magnetizer" claims it will save up to 25% on your gas mileage. This "ingenious device ...changes the molecular structure of fuel-negatively charged fuel and oxygen molecules attract for combustion efficiency." A press report stated "trees would be sprayed this week due to an infestation of gypsy moths and aphids. The material applied is environmentally safe since it is an organic compound, not a chemical." There have been reports of several errors concerning ozone:
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Journal of Chemical Education
"Clean fuels-methanol, ethanol, and natural gas ... are considered improvements on gasoline, which when burned produces carbon dioxide-the key ingredient of ozone." "Freon, the principle culprit, was ... replaced by hydrocarbons such as carbon dioxide." "Trees are a major source of hydrocarbons, a main ingredient of ozone." "It may make more sense to go after another component of o z o n e t h e N0,'s." "The commission also called for a ban of all containers made with chlorofluorocarbons,which destroy the atmosphere." While reports such as those cited above may appear to be humorous, they should be viewed with alarm. Students should profit from a study of the confusion in the media.
