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Dichlorodifluoromethane (R-12) is a colorless gas popularly known by the genericized brand name Freon (as Freon-12). It is a chlorofluorocarbon halomethane (CFC) used as a refrigerant and aerosol spray propellant .
According to ASHRAE standard 34, the R-number of a chemical refrigerant is assigned systematically according to its molecular structure and has between two and four digits. If there are carbon -carbon multiple bonds , there are four digits in all: the number of these bonds is the first digit and the number of carbon atoms minus one (C-1) is next.
Freon-12, for example, indicates a methane derivative (only two numbers) containing two fluorine atoms (the second 2) and no hydrogen (1-1=0). It is therefore CCl 2 F 2. [8] Another equation that can be applied to get the correct molecular formula of the CFC/R/Freon class compounds is to take the numbering and add 90 to it.
'Freon' is the brand name for the refrigerants R-12, R-13B1, R-22, R-410A, R-502, and R-503 manufactured by The Chemours Company, and so is not used to label all refrigerants of this type. They emit a strong smell similar to acetone. [2] Freon has been found to cause damage to human health when inhaled in large amounts.
Bromochlorodifluoromethane (BCF), also referred to by the code numbers Halon 1211 and Freon 12B1, is a haloalkane with the chemical formula C F 2 Cl Br.It is used for fire suppression, especially for expensive equipment or items that could be damaged by the residue from other types of extinguishers. [1]
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]
LibreOffice Calc is the spreadsheet component of the LibreOffice software package. [5] [6]After forking from OpenOffice.org in 2010, LibreOffice Calc underwent a massive re-work of external reference handling to fix many defects in formula calculations involving external references, and to boost data caching performance, especially when referencing large data ranges.
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 ]