1,1,2-Trichloro-1,2,2-trifluoroethane
Encyclopedia
Trichlorotrifluoroethane, also called 1,1,2-Trichloro-1,2,2-trifluoroethane or CFC-113 is a chlorofluorocarbon
. It has the formula CCl2FC-ClF2.
CFC-113 is a very unreactive chlorofluorocarbon, that will stay in the atmosphere
for a great deal of time if it is released. CFC-113 will stay in the atmosphere long enough that it will cycle out of the troposphere
and into the stratosphere
. In the stratosphere, CFC-113 can be broken up by ultraviolet radiation, creating chlorine radicals, which can in turn react with ozone
molecules to form molecular oxygen (O2), leading to the overall depletion of stratospheric ozone. The amount of CFC-113 in the atmosphere has stayed relatively stable, at about 80 parts per trillion, since the early 1990s. http://ccle.ucla.edu/file.php/2529/ozone_08_2_per_pg.pdf
in 1987 called for the phase out of all CFC’s, including CFC-113 by 2010.
The molecular weight of CFC-113 is 187.375 g/mol.
The mean residence time of CFC-113 is approximately 90 years. This long mean residence time means that it will stay in the atmosphere long enough that it will make its way into the stratosphere and can begin to deplete the stratospheric ozone.
CFC-113 also is a very volatile and apolar molecule so it was used as a foaming agent in the production of packaging material, insulation, foams for cushioning, and things like shoe soles.
CFC-113 has such a low flammability and low toxicity that it was also used as a cleaner for delicate electrical equipment, fabrics, and even metals. Because it would not harm the product it was cleaning, catch fire with a spark or react with other chemicals it was ideal for this purpose.http://www.ciesin.org/TG?OZ/prodcfcs.html
CFC-113 in laboratory analytics has been replaced by other solvents.
(Cl
) then decomposes ozone as follows:
Cl + O3 => ClO + 02
This will occur in only half a second. It is followed by:
ClO + O => Cl + O2
taking only a few minutes, regenerating the atomic chlorine to destroy more O3. The Cl atoms thus act as a catalyst, with each able to destroy 100,000 O3 molecules during its atmospheric lifetime of 1-2 years. In some parts of the world, these reactions have significantly thinned the Earth's natural stratospheric ozone layer that shields the biosphere against solar UV radiation; increased UV levels at the surface can cause skin cancer or even blindness.
Chlorofluorocarbon
A chlorofluorocarbon is an organic compound that contains carbon, chlorine, and fluorine, produced as a volatile derivative of methane and ethane. A common subclass are the hydrochlorofluorocarbons , which contain hydrogen, as well. They are also commonly known by the DuPont trade name Freon...
. It has the formula CCl2FC-ClF2.
CFC-113 is a very unreactive chlorofluorocarbon, that will stay in the atmosphere
Atmosphere
An atmosphere is a layer of gases that may surround a material body of sufficient mass, and that is held in place by the gravity of the body. An atmosphere may be retained for a longer duration, if the gravity is high and the atmosphere's temperature is low...
for a great deal of time if it is released. CFC-113 will stay in the atmosphere long enough that it will cycle out of the troposphere
Troposphere
The troposphere is the lowest portion of Earth's atmosphere. It contains approximately 80% of the atmosphere's mass and 99% of its water vapor and aerosols....
and into the stratosphere
Stratosphere
The stratosphere is the second major layer of Earth's atmosphere, just above the troposphere, and below the mesosphere. It is stratified in temperature, with warmer layers higher up and cooler layers farther down. This is in contrast to the troposphere near the Earth's surface, which is cooler...
. In the stratosphere, CFC-113 can be broken up by ultraviolet radiation, creating chlorine radicals, which can in turn react with ozone
Ozone
Ozone , or trioxygen, is a triatomic molecule, consisting of three oxygen atoms. It is an allotrope of oxygen that is much less stable than the diatomic allotrope...
molecules to form molecular oxygen (O2), leading to the overall depletion of stratospheric ozone. The amount of CFC-113 in the atmosphere has stayed relatively stable, at about 80 parts per trillion, since the early 1990s. http://ccle.ucla.edu/file.php/2529/ozone_08_2_per_pg.pdf
History
CFC-113 was originally used as a coolant in air conditioners and refrigerators because of its low boiling point and relative inertness. CFC-113 was also formerly used as a solvent with which to clean electronics, especially phones. It is estimated that in 1988, 360 million pounds of CFC-113 were being used, accounting for 17% of the total amount of chlorofluorocarbons produced globally. The Montreal ProtocolMontreal Protocol
The Montreal Protocol on Substances That Deplete the Ozone Layer is an international treaty designed to protect the ozone layer by phasing out the production of numerous substances believed to be responsible for ozone depletion...
in 1987 called for the phase out of all CFC’s, including CFC-113 by 2010.
Chemistry
CFC-113 has two constitutional isomers: 1,1,1-trichlorotrifluoroethane and 1,1,2-trichlorofluoroethane. Both have a two-carbon backbone. The first isomer has all three chlorines attached to one carbon, and all three fluorines attached to the other. 1,1,2-trichlorotrifluoroethane has two chlorines and one fluorine attached to one carbon, and one chlorine and two fluorines bonded to the other carbon.The molecular weight of CFC-113 is 187.375 g/mol.
The mean residence time of CFC-113 is approximately 90 years. This long mean residence time means that it will stay in the atmosphere long enough that it will make its way into the stratosphere and can begin to deplete the stratospheric ozone.
Uses
CFC-113 was one of the many CFCs that were produced to eliminate toxic and flammable substances in the areas that they were used. It has been used as a cooling agent in refrigerants and air conditioners, aerosol propellant, and a cleansing agent for electrical and electronic components. CFC-113 is one of the three most popular CFCs, along with CFC-11 and CFC-12 and saw much use in its time. CFC-113 has a unique property that makes it perfect for cooling systems. When it is in a gas form and compressed, it heats up, when it is expanded, it cools. This makes them ideal for the vapor compression cycle systems. They were also very desirable because of their low toxicity, non-flammability, thermophysical properties, and normal boiling point.CFC-113 also is a very volatile and apolar molecule so it was used as a foaming agent in the production of packaging material, insulation, foams for cushioning, and things like shoe soles.
CFC-113 has such a low flammability and low toxicity that it was also used as a cleaner for delicate electrical equipment, fabrics, and even metals. Because it would not harm the product it was cleaning, catch fire with a spark or react with other chemicals it was ideal for this purpose.http://www.ciesin.org/TG?OZ/prodcfcs.html
CFC-113 in laboratory analytics has been replaced by other solvents.
Ozone destruction
With its long atmospheric lifetime of about 90 years, CFC-113 (like other CFCs) has time to reach the stratosphere where sunlight in the 190-225 nm (UV) range can remove individual chlorine atoms. The atomic chlorineChlorine
Chlorine is the chemical element with atomic number 17 and symbol Cl. It is the second lightest halogen, found in the periodic table in group 17. The element forms diatomic molecules under standard conditions, called dichlorine...
(Cl
CL
CL may refer to:*Certificated Location, a Caravan Club site*Clay , a type of soil*150 in Roman numerals*Light cruiser hull classification in the US Navy*Mercedes-Benz CL-Class, an automobile...
) then decomposes ozone as follows:
Cl + O3 => ClO + 02
This will occur in only half a second. It is followed by:
ClO + O => Cl + O2
taking only a few minutes, regenerating the atomic chlorine to destroy more O3. The Cl atoms thus act as a catalyst, with each able to destroy 100,000 O3 molecules during its atmospheric lifetime of 1-2 years. In some parts of the world, these reactions have significantly thinned the Earth's natural stratospheric ozone layer that shields the biosphere against solar UV radiation; increased UV levels at the surface can cause skin cancer or even blindness.