- Branche: Education
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Founded in 1879 and named after Texas' greatest hero General Sam Houston, Sam Houston State University is public shcool within the Texas state university system and located in Huntsville, Texas.
It's a multicultural institution that offers 79 bachelorette degree programs, 54 masters and five ...
CCl<sub>2</sub>F<sub>2</sub>, This compound, also known as Freon<sup>®</sup> 12 or CFC-12, is the primary CFC that has been linked to the catalytic destruction of ozone. Even though the compound is found in very small concentrations, its properties make it a significant factor in stratospheric chemistry. CCl<sub>2</sub>F<sub>2</sub> absorbs UV light in the upper stratosphere where it arrives decades after being released in the troposphere. CFCs, which were originally created by Dupont corporation, were used as refrigerants for everything from air conditioning to home refrigerators because they are non-toxic and extremely unreactive (in the troposphere). It is this unreactivity that makes them such a problem for the atmosphere, because they are able to last long enough to make it to the stratosphere, where they cause so many problems. CCl<sub>2</sub>F<sub>2</sub> production, along with all CFCs, has been banned since the mid 1990s, but some scientists believe that the damage has already been done. For further reading see the term ozone.
Industry:Chemistry; Weather
CCl<sub>4</sub>, a compound consisting of a carbon and 4 chlorines that is active in ozone depletion when the compound is broken down and releases chlorine atoms (radicals). Chlorine reacts with the ozone creating diatomic oxygen and chlorine monoxide which cycles back to chlorine radicals.
Industry:Chemistry; Weather
CF<sub>4</sub>, is known as Freon 14, carbon tetrafluoride is a stable, non-flammable, colorless gas. It absorbs light at 8 mm (in the infrared), is very stable, and does not react with water. This compound is theoretically considered a likely candidate for warming the earth during the next ice age.
Industry:Chemistry; Weather
CH<sub>2</sub>=CH-CH=CH<sub>2</sub>, is produced during a petrochemical combustion. It is also leaked into the atmosphere from the storage of petrochemicals. Typical half-life in the atmosphere is around 2 hours. It is also a known human carcinogen.
Industry:Chemistry; Weather
CH<sub>2</sub>CHCN, a bad smelling, colorless liquid that is used in plastics, and when these plastics are burned they produce fumes that are carcinogenic because of the 2-propenenitrile.
Industry:Chemistry; Weather
CH<sub>2</sub>Cl<sub>2</sub>, a clear, colorless organic solvent that has a sweet but mild odor and does not occur naturally in the environment. Its principle use is as a solvent in paint removers and as an aerosol propellant in paints and automotive spray products. In addition, it is used as a blowing and cleaning agent of metal, as a solvent in the production of polycarbonate resins, and in film processing, as well as many other industrial applications. In the food industry, it is used as an extraction solvent for caffeine, spices, and hops. All of these applications result in the release of dichloromethane into the environment, with the primary sources being the industries that manufacture the chemical or use it in production, such as the plastic and synthetics manufacturers, as well as the electronics industry. Upon release of the liquid chemical into the environment, dichloromethane quickly evaporates to a gas, where it is then degraded by photochemically produced products in the air. Because of its reactivity in the troposphere, it is not believed to react with ozone in the upper atmosphere. Despite its solubility in water, it has low acute toxicity to aquatic animals. In animals (as well as humans), dichloromethane is metabolized into carbon monoxide, which has a higher affinity for the heme groups in hemoglobin than does oxygen and results in deprivation of oxygen. Interestingly, dichloromethane has been found to be an antisickling agent in sickle cell hemoglobin.
Industry:Chemistry; Weather
CH<sub>2</sub>ClCH<sub>2</sub>CH<sub>2</sub>CH<sub>2</sub>Cl, A compound found in the atmosphere composed of a benzene ring and two chlorine atoms in the 1 and 4 positions. It is often used to make mothballs and as a fumigant, this compound is detected in urban atmospheres and in many human tissue samples.
Industry:Chemistry; Weather
CH<sub>2</sub>O, A colorless, pungent, carcinogenic, and toxic gas which can irritate membranes. It is used as formalin in its aqueous state (37 %). Formaldehyde is reactive due to its carbonyl functional group. In the oxidation of hydrocarbons in the atmosphere, formaldehyde is one of many aldehydes that is produced especially in urban environments.
Industry:Chemistry; Weather
CH<sub>2</sub>O<sub>2</sub>, A weak acid that photolytically reacts in the atmosphere forming COOH radical and H radical. This compound often reacts with the hydroxyl radical and atomic oxygen to form formic acid and a hydroperoxy radical. This is a sink for the hydroxyl radical and it also helps drive other reactions with the addition of hydroperoxy radicals to the atmosphere.
Industry:Chemistry; Weather
CH<sub>3</sub><sup>. </sup> is formed, along with water, from the reaction of methane (CH<sub>4</sub>) and the hydroxyl radical (OH<sup>. </sup>). This begins a series of reactions that eventually produces ozone(O<sub>3</sub>).
Industry:Chemistry; Weather
