Dichlorodifluoromethane

chemical substances

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This entry is made by Compilation and application of scientific encyclopedia entries of "Science Popularization China" to examine.

Dichlorodifluoromethane, also known as Freon-12, is an organic compound with the chemical formula CCl two F two It can be used as refrigerant, fire extinguishing agent, insecticide and spray agent, and is also the raw material of fluorine resin.

Chinese name: Dichlorodifluoromethane
Foreign name: dichlorodifluoromethane
Alias: Freon-12 、 Difluorodichloromethane
chemical formula: CCl two F two
molecular weight: one hundred and twenty point nine one four
CAS login number: 75-71-8
EINECS login number: 200-893-9

Melting point: -158 ℃
Boiling point: -29.8 ℃
Water solubility: Insoluble
Appearance: Colorless and odorless gas
Flash point: 11 ℃
Security description: S7；S16；S23；S24/25；S36/37；S45；S59；S61
Hazard symbol: Xn；N
Hazard description: R20；R59

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Physical and chemical properties

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Melting point: - 158 ℃

Boiling point: - 29.8 ℃

Flash point: 11 ℃

Refractive index: 1.169

Critical temperature: 111.8 ℃

Critical pressure: 4.12MPa

Saturated vapor pressure: 568kPa (20 ℃)

Appearance: colorless and odorless gas

Solubility: insoluble in water, soluble in ethanol and ether^[10]

Molecular structure data

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Molar refractive index: 16.67

Molar volume (cm three /mol）：78.7

Isotonic specific volume (90.2K): 352.5

Surface tension (dyne/cm): 38.4

Polarization (10 -24 cm three ）：18.14^[10]

Calculate chemical data

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Reference value for drainage parameter calculation (XlogP): 2.3

Number of hydrogen bond donors: 0

Number of hydrogen bond receptors: 2

Number of rotatable chemical bonds: 0

Number of tautomers: 0

Topological molecular polar surface area: 0

Number of heavy atoms: 5

Surface charge: 0

Complexity: 30.6

Number of isotope atoms: 0

Determine the number of atomic structure centers: 0

Number of uncertain atomic structure centers: 0

Determine the number of chemical bond structure centers: 0

Number of uncertain chemical bond structure centers: 0

Number of covalent bond units: 1^[10]

toxicology data

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1. Acute toxicity

LC fifty : 800000ppm (inhaled by rats, 30min)

2. Subacute and chronic toxicity

In rats and guinea pigs, the inhalation concentration was 4000 mg/m3, and more than 90 days later, 15 animals died from 1 to 2, with liver fat changes, focal necrosis, and non-specific changes in the lungs.

3. Others

TCLo: 200000ppm (human inhalation, 30min).^[10]

Ecological data

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1. Biodegradability

Aerobic biodegradation: 672~4032h

Anaerobic biodegradation: 2688~16128h

2. Non biodegradable

Maximum optical absorption of photolysis - high:<200nm

Photooxidation half-life in air: 2118~21180h

3. Other harmful effects

This substance is harmful to the environment, and special attention should be paid to atmospheric pollution. Its ozone depletion potential ODP is 1, which is extremely destructive to the atmospheric ozone layer.^[10]

Storage method

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It shall be stored in a cool and ventilated special warehouse for non combustible gas. Keep away from kindling and heat sources. The warehouse temperature should not exceed 30 ℃. It shall be stored separately from oxidants, alkali metals, alkaline earth metals and edible chemicals, and mixed storage is strictly prohibited. The storage area shall be equipped with leakage emergency treatment equipment.^[1]

purpose

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It can be used as refrigerant, fire extinguishing agent, insecticide and spray agent, and is also the raw material of fluorine resin.

First aid measures

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Inhalation: (1) If the concentration exceeds 10000 ppm, the central nervous system will be affected. Symptoms may include mild nose, throat, upper respiratory tract irritation, mild headache, dizziness, and lethargy. (2) The effects of inarticulate speech, tinnitus, restlessness (40000 ppm concentration) and uncoordinated action (about 100000 ppm) will become more obvious with the increase of concentration. (3) More serious exposure may cause irregular heartbeat and cardiac arrest, leading to death.

Skin contact: Frozen injury (non irritating gas) may be caused by the narrow range of contact with gas or liquid.

Eye contact: Liquid may cause slight irritation and frostbite.

Substance toxicity

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Toxicity test data reported in literature and journals
number	Toxicity type	test method	Test object	Dosage	Toxic effect
one	acute toxicity	inhalation	human beings	200000 ppm/30M	Eye toxicity - conjunctival irritation Lung, chest or respiratory toxicity - fibroalveolar inflammation Hepatotoxicity - other changes
two	acute toxicity	Oral	Rat	>5600 μg/kg	No values other than lethal dose were reported for detailed effects
three	acute toxicity	inhalation	Rat	>80 pph/4h	No values other than lethal dose were reported for detailed effects
four	acute toxicity	inhalation	mice	3348 gm/m three /3h	Behavioral toxicity - sleep Behavioral toxicity - tremor Behavioral toxicity - excitement
five	acute toxicity	inhalation	rabbit	80 pph/30M	No values other than lethal dose were reported for detailed effects
six	acute toxicity	inhalation	guinea pig	80 pph/30M	No values other than lethal dose were reported for detailed effects
seven	Chronic toxicity	Oral	Rat	2548 mg/kg/26W-I	Behavioral toxicity - classical conditioned reflex changes Blood toxicity - red blood cell count changes Biochemical toxicity - inhibition or induction of cholinesterase
eight	Chronic toxicity	inhalation	Rat	4136 mg/m three /8H/6W-I	Lung, chest or respiratory toxicity - chronic pulmonary edema Chronic disease related toxicity - death
nine	Chronic toxicity	inhalation	Rat	3997 mg/m three /90D-C	Lung, chest or respiratory toxicity - chronic pulmonary edema Chronic disease related toxicity - death
ten	Chronic toxicity	inhalation	monkey	3997 mg/m three /90D-C	Lung, chest or respiratory toxicity - chronic pulmonary edema
eleven	Chronic toxicity	inhalation	rabbit	3997 mg/m three /90D-C	Lung, chest or respiratory toxicity - chronic pulmonary edema
twelve	Chronic toxicity	inhalation	guinea pig	3997 mg/m three /90D-C	Lung, chest or respiratory toxicity - chronic pulmonary edema Hepatotoxicity - hepatitis (hepatocyte necrosis), diffusion Chronic disease related toxicity - death