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Chlorofluorocarbons (CFCs): when derived from methane and ethane these compounds have the formulae CCl m F 4−m and C 2 Cl m F 6−m, where m is nonzero. Hydro-chlorofluorocarbons (HCFCs): when derived from methane and ethane these compounds have the formula CCl m F n H 4−m−n and C 2 Cl x F y H 6−x−y, where m, n, x, and y are nonzero.
Abundances are given as pollution free monthly mean mole fractions in parts-per-trillion. Atmospheric concentration of CFC-113 since year 1992. CFC-113 is a very unreactive chlorofluorocarbon. It remains in the atmosphere about 90 years, [9] sufficiently long that it will cycle out of the troposphere and into the stratosphere.
1,2-Dichlorotetrafluoroethane, or R-114, also known as cryofluorane , is a chlorofluorocarbon (CFC) with the molecular formula ClF 2 CCF 2 Cl. Its primary use has been as a refrigerant. It is a non-flammable gas with a sweetish, chloroform-like odor with the critical point occurring at 145.6 °C and 3.26 MPa. When pressurized or cooled, it is a ...
Trichlorofluoromethane, also called freon-11, CFC-11, or R-11, is a chlorofluorocarbon (CFC). It is a colorless, faintly ethereal, and sweetish-smelling liquid that boils around room temperature. [5] CFC-11 is a Class 1 ozone-depleting substance which damages Earth's protective stratospheric ozone layer. [6]
Perfluoroalkanes are very stable because of the strength of the carbon–fluorine bond, one of the strongest in organic chemistry. [4] Its strength is a result of the electronegativity of fluorine imparting partial ionic character through partial charges on the carbon and fluorine atoms, which shorten and strengthen the bond (compared to carbon-hydrogen bonds) through favorable covalent ...
1-Chloro-1,1-difluoroethane (HCFC-142b) is a haloalkane with the chemical formula C H 3 C Cl F 2.It belongs to the hydrochlorofluorocarbon (HCFC) family of man-made compounds that contribute significantly to both ozone depletion and global warming when released into the environment.
The debate about the benefits and risks of fluoride is ongoing, as RFK Jr. — incoming President Trump’s pick for HHS secretary — pushes to remove it from the U.S. water supply. "Fluoride is ...
Starting in the 2010s, despite a global ban on the production of CFCs, five of these ozone-damaging emissions were on the rise. [ 5 ] The atmospheric abundance of CFC-13 rose from 3.0 parts per trillion (ppt) in year 2010 to 3.3 ppt in year 2020 based on analysis of air samples gathered from sites around the world. [ 10 ]