Fluoroform

Fluoroform
Fluoroform
Are common
Systematic ; name	trifluoromethane
Abbreviations	R-23, HFC-23,
Traditional names	freon 23
Chem. formula	CHF₃
Physical properties
condition	colorless gas
Molar mass	70.0141 g / mol
Density	0.516 g / cm³
Dynamic viscosity	14.4 · 10 −6 Pa · s
Thermal properties
T. melt.	−155.2 ° C
T. bale.	−82.1 ° C
Cr. point	32.3 ° C, 50.5 atm
Cr. pace.	25.7 ° C
Cr. pressure	4.816 MPa
Like heat resistant.	51.577 J / (mol · K)
Specific Heat of Evaporation	257.91 J / kg
Chemical properties
Solubility in other substances	soluble in organic compounds
Structure
Dipole moment	1,649 D
Classification
Reg. CAS number
PubChem
Reg. EINECS number
Smiles
Inchi
Reg. EC number	200-872-4
RTECS	PB6900000
Chebi	and
ChemSpider
Security
Toxicity	0 2 0

Fluoroform is the trivial name for trifluoromethane ( Freon 23, Freon 23, R23, HFC 23). Fluoroform is an organofluorine compound belonging to the fluorinated hydrocarbons of the methane series. Fluoroform is used as a high-pressure refrigerant to obtain temperatures up to minus 100 ° C and a dry etching reagent in the manufacture of ultra-large integrated circuits. ^[one]

Fluoroform CHF ₃ ( trifluoromethane ) is a chemical organic inert compound . The compound is one of the haloforms ; a class of compounds of the formula C H X ₃ (where X is halogen ).

Fluoroform is used in various fields and is produced as a by-product of Teflon production. It is also created biologically in small amounts, apparently during decarboxylation of trifluoroacetic acid .

Properties

Heat of formation ΔH ° ₂₉₈ : 162.6 ± 0.6 kcal / mol,
Specific heat: 0.28 kcal / kg
Steam pressure: ${\mbox{lg}}P=8,193-{\frac {1004,83}{\mbox{T}}}$ ${\ displaystyle {\ mbox {lg}} P = 8.193 - {\ frac {1004.83} {\ mbox {T}}}}$ ${\mbox{lg}}P=8,193-{\frac {1004,83}{\mbox{T}}}$ .

Unlike chloroform , hydrogen protonization does not occur under the action of alkalis.

Industrial Application

CHF _{3 is} used in the semiconductor industry for plasma etching of silicon oxide and silicon nitride . Known as R-23 or HFC-23 as a high-pressure refrigerant (mainly for low temperatures, up to about −100 ° C), and sometimes as a replacement for trifluorochloromethane , which is a by-product of its production.

When used as a fire extinguishing agent, fluoroform has the brand name of DuPont - FE-13. Fluoroform is recommended for these purposes because of its low toxicity , low reactivity and high density.

Organic Chemistry

CHF ₃ is a reagent for creating sources of "CF ₃ ^- " for deprotonation . The molecule is low toxic and has a pK _a = 25-28. This substance is a precursor for the production of CF ₃ Si (CH ₃ ) ₃

Synthesis

Fluoroform was first obtained by Maurice Meslans as a result of a violent reaction of iodoform with dry silver fluoride in 1894. The reaction was improved by Otto Raff by replacing silver fluoride with a mixture of mercury fluoride and calcium fluoride . The exchange reaction occurs between iodoform and bromoform , as well as during the exchange of the first two halogen fluorine atoms.

Fluoroform is obtained by the action of SbF ₃ Cl ₂ • 2HF on chloroform ; it is formed by the action of HgF ₂ on CHBrF ₂ ; under the action of alkalis on trifluoromethyl- containing carbonyl compounds : ${\mbox{CF}}_{3}+{\mbox{COR}}+{\mbox{KOH}}\longrightarrow {\mbox{CF}}_{2}{\mbox{H}}+{\mbox{RCOOK}}$ ${\ displaystyle {\ mbox {CF}} _ {3} + {\ mbox {COR}} + {\ mbox {KOH}} \ longrightarrow {\ mbox {CF}} _ {2} {\ mbox {H}} + {\ mbox {RCOOK}}}$ , as well as trifluoromethyl derivatives of some cements:

{\mathsf {{\begin{matrix}{\mbox{CF}}_{3}{\mbox{SO}}_{2}{\mbox{K}}\\({\mbox{CF}}_{3})_{3}{\mbox{P}}\\({\mbox{CF}}_{3})_{2}{\mbox{Hg}}\end{matrix}}{\Bigg \}}{\xrightarrow {\mbox{KOH}}}CF_{3}H+{\Bigg \{}{\begin{matrix}{\mbox{K}}_{2}{\mbox{SO}}_{3}\\{\mbox{K}}_{2}{\mbox{HPO}}_{3}\\{\mbox{Hg(OH)}}_{2}\end{matrix}}}}

{\ displaystyle {\ mathsf {{\ begin {matrix} {\ mbox {CF}} _ {3} {\ mbox {SO}} _ {2} {\ mbox {K}} \\ ({\ mbox {CF }} _ {3}) _ {3} {\ mbox {P}} \\ ({\ mbox {CF}} _ {3}) _ {2} {\ mbox {Hg}} \ end {matrix}} {\ Bigg \}} {\ xrightarrow {\ mbox {KOH}}} CF_ {3} H + {\ Bigg \ {} {\ begin {matrix} {\ mbox {K}} _ {2} {\ mbox {SO }} _ {3} \\ {\ mbox {K}} _ {2} {\ mbox {HPO}} _ {3} \\ {\ mbox {Hg (OH)}} _ {2} \ end {matrix }}}}}

Trifluoromethane as a Greenhouse Gas

CHF ₃ is a powerful greenhouse gas . Was given ^{[by whom?} ^] assessment of the comparison of carbon dioxide and trifluoromethane for atmospheric effects: one ton of trifluoromethane has the same effect as 11,700 tons of carbon dioxide. More recent work has shown that this equivalence in the GWP rating is slightly greater than 14,800 for trifluoromethane. The lifetime of trifluoromethane in the atmosphere will be 270 years.

Developing countries have become the largest producers of fluoroform in recent years, according to the secretariat of the World Meteorological Organization. Fluoroform emissions are accounted for in the Kyoto Protocol . To mitigate the detrimental effects of this gas, fluoroform can be destroyed using electric plasma technology or burning at high temperatures.

Additional Physical Properties

Property	Value
Density (ρ) at −100 ° C (liquid)	1.52 g / cm³
Density (ρ) at −82.1 ° C (liquid)	1.431 g / cm³
Density (ρ) at −82.1 ° C (gas)	4.57 kg / m³
Density (ρ) at 0 ° C (gas)	2.86 kg / m³
Density (ρ) at 15 ° C (gas)	2.99 kg / m³
Critical density (ρ _c )	7.52 mol / liter
Compressibility factor (Z)	0.9913
Peripheral Factor (ω)	0.26414

Notes

↑ Organofluorine Industrial Products: Ref. Edition / B.N. Maksimov, V.G. Barabanov, I.L. Serushkin et al. - 2nd ed., trans. and additional .. - St. Petersburg: "Chemistry", 1996. - 544 p. - ISBN 5-7245-1043-X .