It:dichlorodifluromethane

Dichlorodifluoromethane

2D Structure

3D Structure

Chemical Name

dichloro-difluoro-methane

Formula

CCl₂F₂

Synonyms

Fluorocarbon 12, Refrigerant 12, Freon 12,

Propellant 12, Halon 122, FC 12, Freon F-12.

CAS No.

[75-71-8]

Beilstein No.

1732393

Properties

Type of Substance

Acyclic

Boiling Point

-29.8°C / -21.6°F

Melting Point

-157.7°C / -252°F

Density

1.293

Solubility

Nearly insoluble in water;

solubale in most organic solvents.

Introduction

Dichlorodifluoromethane is a colorless, nonflammable gas with almost no odor (ether-like odor at extremely high concentrations).It is used as a refrigerant gas, an aerosol propellant, in plastics, and as a leak detecting agent until its manufacture was discontinued in 1995, due to concerns about damage to the ozone layer. The ozone depletion potential of R-12 is 0.82, which is relatively high.

History

The Major use of dichlorodifluoromethane is as a refrigerant gas. Refrigerants like sulfur dioxide and methyl chloride (used in early days when refrigerators were invented) were causing people to die. Ammonia had an equally serious toxic effect if it leaked. Refrigeration engineers searched for acceptable substitutes until the 1920s, when a number of synthetic refrigerants called halocarbons or CFCs (chlorofluorocarbons) were developed by Frigidaire. The best known of these substances was patented under the brand name of Freon. Chemically, Freon was created by the substitution of two chlorine and two fluorine atoms for the four hydrogen atoms in methane (CH₄); the result, dichlorodifluoromethane (CCl₂F₂), is odourless and is toxic only in extremely large doses.