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Dichlorofluoromethane or Freon 21 or R 21 is a halomethane or hydrochlorofluorocarbon with the formula CHCl 2 F. It is a colorless and odorless gas. It is a colorless and odorless gas. It is produced by fluorination of chloroform using a catalyst such as antimony trifluoride : [ 4 ]
It is a chlorofluorocarbon halomethane (CFC) used as a refrigerant and aerosol spray propellant. In compliance with the Montreal Protocol, its manufacture was banned in developed countries (non-article 5 countries) in 1996, and in developing countries (Article 5 countries) in 2010 out of concerns about its damaging effect on the ozone layer. [5]
Selenium, which is an essential element for animals and prokaryotes and is a beneficial element for many plants, is the least-common of all the elements essential to life. [ 3 ] [ 63 ] Selenium acts as the catalytic center of several antioxidant enzymes, such as glutathione peroxidase , [ 11 ] and plays a wide variety of other biological roles .
Chloroform, [10] or trichloromethane (often abbreviated as TCM), is an organochloride with the formula C H Cl 3 and a common solvent.It is a volatile, colorless, sweet-smelling, dense liquid produced on a large scale as a precursor to refrigerants and PTFE. [11]
HCFC-123 is used in large tonnage centrifugal chiller applications, and is the most efficient refrigerant currently in use in the marketplace for HVAC applications. HCFC-123 is also used as a testing agent for bypass leakage of carbon adsorbers in gas filtration systems, and as the primary chemical in Halotron I fire-extinguishing agent. [2]
Pyrolysis of a mixture of dichlorofluoromethane and chlorofluoromethane gives hexafluorobenzene: [1] 3 CHCl 2 F + 3 CH 2 ClF → C 6 F 6 + 9 HCl. It was used as a refrigerant and has an ozone depletion potential of 0.02.
Both animals and plants are used to provide pleasure, through a range of activities including keeping pets, hunting, fishing, and gardening. A wide variety of animals are kept as pets , from invertebrates such as tarantulas and octopuses, insects including praying mantises , [ 52 ] reptiles such as snakes and chameleons , [ 53 ] and birds ...
1,1-Dichloro-1-fluoroethane is mainly used as a solvent and foam blowing agent under the names R-141b and HCFC-141b. It is a class 2 ozone depleting substance undergoing a global phaseout from production and use under the Montreal Protocol since the late 1990s. It is being replaced by HFCs within some applications. [4]