Vapor-liquid coexistence curves in the critical region and the critical temperatures and densities of difluoromethane and pentafluoroethane
- Keio Univ., Yokohama (Japan). Dept. of Mechanical Engineering
The vapor-liquid coexistence curves in the critical region of difluoromethane (HFC-32) and pentafluoroethane (HFC-125) were measured by a visual observation of the meniscus in an optical cell. Seventeen saturated-liquid and 13 saturated-vapor densities have been measured in a temperature range from 330 K to the critical temperature, corresponding to a density range from 218 to 790 kg/m[sup 3] for HFC-32. Sixteen saturated-liquid and 13 saturated-vapor densities have been measured in a temperature range from 331 K to the critical temperature, corresponding to a density range from 342 to 895 kg/m[sup 3] for HFC-125. The experimental uncertainties of temperature and density measurements are estimated to be within [+-]10 mK and between [+-]0.10% and [+-]0.42%, respectively. Not only the level of the meniscus disappeared but also the intensity of the critical opalescence was considered in the determination of the critical temperature and density of HFC-32, being 351.255 [+-] 0.010 K and 424 [+-] 1 kg/m[sup 3], and those of HFC-125, being 339.165 [+-] 0.010 K and 568 [+-] 1 kg/m[sup 3].
- OSTI ID:
- 6794873
- Journal Information:
- Journal of Chemical and Engineering Data; (United States), Vol. 40:1; ISSN 0021-9568
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
54 ENVIRONMENTAL SCIENCES
FLUORINATED ALIPHATIC HYDROCARBONS
DENSITY
REFRIGERANTS
CHLOROFLUOROCARBONS
CRITICAL TEMPERATURE
EXPERIMENTAL DATA
MATERIAL SUBSTITUTION
THERMODYNAMIC PROPERTIES
DATA
FLUIDS
HALOGENATED ALIPHATIC HYDROCARBONS
INFORMATION
NUMERICAL DATA
ORGANIC CHLORINE COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC FLUORINE COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
PHYSICAL PROPERTIES
TRANSITION TEMPERATURE
WORKING FLUIDS
320106* - Energy Conservation
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540120 - Environment
Atmospheric- Chemicals Monitoring & Transport- (1990-)