how are cfcs broken down by uv radiation?
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One of the few forces that can break up CFC molecules is ultraviolet radiation. ... Bombarded by the sunÕs ultraviolet energy, CFC molecules break up and release chlorine atoms. Free chlorine atoms then react with ozone molecules, taking one oxygen atom to form chlorine monoxide and leaving an ordinary oxygen molecule.
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Stratospheric ozone is formed naturally by chemical reactions involving solar ultraviolet radiation (sunlight) and oxygen molecules, which make up 21% of the atmosphere. In the first step, solar ultraviolet radiation breaks apart one oxygen molecule (O2) to produce two oxygen atoms (2 O) (see Figure Q2-1).
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Because of their relative stability, CFCs rise into the stratosphere where they are eventually broken down by ultraviolet (UV) rays from the Sun. This causes them to release free chlorine. The chlorine reacts with oxygen which leads to the chemical process of destroying ozone molecules.
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The atmospherically benign HFC refrigerants will remain in production, but CFC and HCFC refrigerants will be phased out. Production of CFCs ceased in 1995. ... Health Issues: CFCs and HCFCs are lighter than air, so they rise into the stratosphere, where ultraviolet light frees the chlorine.
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Montreal Protocol parties achieve complete phase-out of ozone-depleting CFCs. ... More than 98% of the CFCs used in MDIs have already been phased out, and will disappear completely in 2016, a significant milestone following 30 years of concerted global action to protect the ozone layer.
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CFCs and their associated compounds were developed in the early 1900s as a non-toxic, non-flammable solution to other more dangerous products such as ammonia. ... When the CFCs reach the ozone layer, ultraviolet radiation occurring at this altitude breaks down the compound and releases the chlorine.
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Hong Kong (CNN) A mystery source of banned, ozone-destroying chemicals has been pinpointed to eastern China. Scientists noted a spike in the amount of chlorofluorocarbons, or CFCs, in the atmosphere last year, despite a global ban on their use. ... A global phaseout of CFCs has been in place since 2010.
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Chlorofluorocarbons (CFCs), including Freon, were used extensively as aerosol propellants. ... CFCs react with chlorine and break down, thereby destroying the ozone layer and allowing more radiation from the sun than is normal to reach the earth. Aerosol products have many uses, from hair care to cleaning and disinfecting.
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Perfluorocarbons are powerful greenhouse gases that were introduced as alternatives to ozone depleting substances. PFCs replace chlorofluorocarbons (CFCs) in manufacturing semiconductors. They are also used as solvents in the electronics industry, and as refrigerants of some specialized refrigeration systems.
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Climate change While acting to destroy ozone, CFCs and HCFCs also act to trap heat in the lower atmosphere, causing the earth to warm and climate and weather to change. ... HFCs, CFCs and HFCs are a subset of a larger group of climate changing gases called greenhouse gases (GHGs).
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CFC starts out as a liquid. The pump pushes the CFC through a series of coils in the freezer area. There the chemical turns to a vapour. When it does, it soaks up some of the heat that may be in the freez- er compartment.
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The ozone layer, which lies high up in the atmosphere, shields us from harmful ultraviolet (UV) rays that come from the Sun. Unfortunately we punched a hole in it, through the use of gases like chlorofluorocarbons (CFCs) in spray cans and refrigerants, which break down ozone molecules in the upper atmosphere.
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Ozone depletion occurs when chlorofluorocarbons (CFCs) and halons—gases formerly found in aerosol spray cans and refrigerants—are released into the atmosphere (see details below).
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Chlorofluorocarbons (CFCs) are a group of odorless manufactured chemicals. Because they damage the earth's ozone layer, CFCs have been banned since 1996.
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Air Conditioner Refrigerant. ... At that time, the refrigerants that used then were known as CFC(chlorofluorocarbons) and HCFCs(hydrochlorofluorocarbons). CFCs are a family of chemicals that contain chlorine, fluorine and carbon. The chlorine content in these compounds cause the depletion of the ozone layer.
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UV or ultraviolet light used a uv bulb whose light sterilized virus and bacteria. MF or microfiltration uses membrane (with pores larger than RO membrane) and rejects solids, particles from water.
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Ozone depletion Man-made compounds such as chlorofluorocarbons (CFCs), hydrofluorocarbons (HCFCs) and halons destroy ozone in the upper atmosphere (stratosphere). The stratospheric ozone layer makes life possible by shielding the earth from harmful ultraviolet (UV-B) rays generated from the sun.