Dichlorodifluoromethane, vaporization

Dichlorodifluoromethane and Trichlorofluoromethane.60 In a flask connected to an ice-cooled reflux condenser, a mixture of 2 moles of carbon tetrachloride and 1 mole of antimony trifluoride is cooled to 0°. After addition of 0.1 mole of antimony pentachloride, the mixture is allowed to warm until the reaction starts. The reaction is regulated by intermittent cooling and heating in order not to overtax the reflux condenser. The uncondensed vapors are led to a receiver cooled with solid carbon dioxide. The distillate is a mixture of CCl3F(b.p. 25°) and CCl2F2(b.p. —30°) whose composition depends on the efficiency of the dephlegmation but is usually 50-50 in a laboratory operation. At the... 

Experience to date indicates equipment selection and system design are important considerations in liquified gas deacidification systems. Operations using magnesium alkoxides or similar materials sensitive to trace quantities of moisture should be conducted under anhydrous conditions, and in-line design constructions leading to vapor locks should be avoided. Components must be selected for exposure to an anhydrous, methanol/dichlorodifluoromethane, alkaline alkoxide solution. 

Chlorotrifluoromethane or Trifluoromono-chloromethane ("Freon—13 ), CC1F3, mw 104.47 colorless, non-toxic, nonflammable gas with ethereal odor fr p —181°, bp —81.4°. Can be prepd from dichlorodifluoromethane in vapor phase with A1C1S catalyst. Used as a refrigerant- also for hardening of metals and in pharmaceutical processing and as dielectric aerospace chemical Refs 1) Beil. 1, < 42> 2) CondChemDict... 

Blends of trichloromonofluoromethane and dichlorodifluoromethane (propellant 11/12) or propellant 11/114/12 produce vapor pressures of 103 84 kPa (15-70 psig) at 21°C, which adequately cover the range of pressures required to produce the proper particle-size distribution for satisfactory aerosol products. Trichloromonofluoromethane is unique among the chlorofluorocarbon propellants in that it is a liquid at room temperature and atmospheric pressure and can be used to prepare a slurry with insoluble medicinal agents. 

Dichlorodifluoromethane is a liquefied gas and exists as a liquid at room temperature when contained under its own vapor pressure, or as a gas when exposed to room temperature and atmospheric pressure. The liquid is practically odorless and colorless. The gas in high concentrations has a faint etherlike odor. Dichlorodifluoromethane is noncorrosive, nonirritating, and nonflammable. 

Dichlorodifluoromethane and dichlorotetrafluoroethane are usually encountered as a liquefied gas and appropriate precautions for handling such materials should be taken. Eye protection, gloves, and protective clothing are recommended. These propellants should be handled in a well-ventilated environment. Chlorofluorocarbon vapors are heavier than air and do not support life therefore, when cleaning large tanks that have contained chlorofluorocarbons, adequate provisions for supply of oxygen in the tanks must be made in order to protect workers cleaning the tanks. 

Properties Colorless gas ethereal odor. Bp -81.4C, fp —181C, heavier than air. Nonflammable Derivation From dichlorodifluoromethane in vapor phase with aluminum chloride catalyst. 

Condensing-Vapor Heat Transfer. The ninth involves the use of a heat-transfer medium other than steam (ammonia and dichlorodifluoromethane are examples) in a vapor-compression cycle. The purpose is to reduce the size of the compressor by using a denser fluid, which will require smaller volumes to be compressed for the same plant capacity. 

Dichlorodifluoromethane (Freon 12, Fluorocarbon 12 [CAS 75-71-81) Mild eye and respiratory tract irritant. Extremely high exposures (eg, 100,000 ppm) can cause coma and cardiac arrhythmias. See also p 209. 1000 ppm 15,000 ppm Colorless gas. Ether-llke odor Is a poor warning property. Vapor pressure is 5.7 mm Hg at 20°C (68°F). Not combustible. Decomposes slowly on contact with water or heat to produce hydrogen chioride, hydrogen fluoride, and phosgene. 

Kang, Y. W. Chung, K. Y. Vapor-liquid equilibria for the systems difluoromethane + chlorodifluoromethane, difluoromethane -I- dichlorodifluoromethane, and difluoromethane + chloromethane at lO.O.deg.C J. Chem. Eng. Data 1996,41,443-445... 

TEMPERATURE Degrees Fahrenheit Fig. 1. Vapor pressure curve for dichlorodifluoromethane (R12). 

A particular refrigerator ccols by evaporating liquefied dichlorcxlifluoromethane, CCI2F2. How many kilograms of this liquid must be evaporated to freeze a tray of water at 0°C to ice at 0°C The mass of the water is 525 g, the heat of fusion of ice is 6.01 kJ/mol, and the heat of vaporization of dichlorodifluoromethane is 17.4kJ/mol. 

TEMPERATURE -- Degrees Fahrenheii Fig. 1. Vapor Pressure Curve for Dichlorodifluoromethane (R-12). 

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