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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.
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 ...
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 . In the stratosphere, CFC-113 can be broken up by ultraviolet radiation (UV, sunlight in the 190-225 nm range), generating chlorine radicals (Cl•), which ...
Some organic constituents such as synthetic hormones, pesticides, phthalates have direct metabolic effects on aquatic biota and even on humans drinking water taken from the river. Understanding such constituents and how they can be identified and quantified is becoming of increasing importance in the understanding of freshwater chemistry.
In 1978 atmospheric levels of CFC-114a were 0.35 ppt. By 2020 the level was up to 1.13 ppt. [13] CFC-114a appears to be emitted into the atmosphere is South East Asia. [10] The atmospheric natural destruction of CFC-114a is by reaction with atomic oxygen, or breakup by ultraviolet light. [10]
Tetrachloro-1,2-difluoroethane is a chlorofluorocarbon known as Freon 112, CFC-112 or R-112. It has a symmetrical structure CCl 2 FCCl 2 F and so can be called symmetrical tetrachlorodifluoroethane. "Symmetrical" may also be abbreviated to "s-" or "sym-". In contrast an asymmetrical isomer has formula CCl 3 CClF 2.
The following chart shows the solubility of various ionic compounds in water at 1 atm pressure and room temperature (approx. 25 °C, 298.15 K). "Soluble" means the ionic compound doesn't precipitate, while "slightly soluble" and "insoluble" mean that a solid will precipitate; "slightly soluble" compounds like calcium sulfate may require heat to precipitate.
The depleting effects of chlorofluorocarbons (CFCs) on ozone over Antarctica has been studied extensively since the 1980s. [7] The low reactivity of CFCs allow it to reach the upper stratosphere , where it interacts with UV-C radiation and forms highly reactive chloride ions that interact with methane. [ 7 ]