Hexafluoroethane

Hexafluoroethane

Names
IUPAC name Hexafluoroethane
Other names Carbon hexafluoride, 1,1,1,2,2,2-Hexafluoroethane, Perfluoroethane, Ethforane, Halocarbon 116, PFC-116, CFC-116, R-116, Arcton 116, Halon 2600, UN 2193
Identifiers
CAS Number	76-16-4 Y
3D model (Jmol)	Interactive image
ChEBI	CHEBI:32905 Y
ChemSpider	6191 Y
ECHA InfoCard	100.000.855
EC Number	200-939-8
PubChem CID	6431
RTECS number	KI4110000
InChI InChI=1S/C2F6/c3-1(4,5)2(6,7)8 Y Key: WMIYKQLTONQJES-UHFFFAOYSA-N Y InChI=1/C2F6/c3-1(4,5)2(6,7)8 Key: WMIYKQLTONQJES-UHFFFAOYAP
SMILES FC(F)(F)C(F)(F)F
Properties
Chemical formula	C2F6
Molar mass	138.01 g.mol−1
Appearance	Colorless odorless gas
Density	5.734 kg.m−3 at 24 °C
Melting point	−100.6 °C (−149.1 °F; 172.6 K)
Boiling point	−78.2 °C (−108.8 °F; 195.0 K)
Solubility in water	0.0015%
log P	2
Vapor pressure	2.967 MPa at 20.1 °C 3.0701 MPa at 21 °C
Henry's law constant (kH)	0.000058 mol.kg−1.bar−1
Hazards
Safety data sheet	See: data page
NFPA 704	0 1 0
Flash point	Non-flammable
Supplementary data page
Structure and properties	Refractive index (n), Dielectric constant (εr), etc.
Thermodynamic data	Phase behaviour solid–liquid–gas
Spectral data	UV, IR, NMR, MS
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Y  (what is YN ?)
Infobox references

3.0701 MPa at 21 °C

Hexafluoroethane is a fluorocarbon counterpart to the hydrocarbon ethane. It is a non-flammable gas negligibly soluble in water and slightly soluble in alcohol.

Hexafluoroethane's solid phase has two polymorphs. In the scientific literature, different phase transition temperatures have been stated. The latest works assign it at 103 K (−170 °C). Below 103 K it has a slightly disordered structure, and over the transition point, it has a body centered cubic structure.

Table of densities:

Vapor density is 4.823 (air = 1), specific gravity at 21 °C is 4.773 (air = 1) and specific volume at 21 °C is 0.1748 m³/kg.

Hexafluoroethane is used as a versatile etchant in semiconductor manufacturing. It can be used for selective etching of metal silicides and oxides versus their metal substrates and also for etching of silicon dioxide over silicon. The primary aluminium and the semiconductor manufacturing industries are the major emitters of hexafluoroethane.

Together with trifluoromethane it is used in refrigerants R508A (61%) and R508B (54%).

Due to the high energy of C-F bonds, it is very inert and thus acts as an extremely stable greenhouse gas, with an atmospheric lifetime of 10,000 years (other sources: 500 years) and a global warming potential (GWP) of 9200. A calculated atmospheric lifetime range of 500 to 10,000 years has been reported. Atmospheric concentration of tetrafluoroethane is 3 pptv (increase by 3 pptv since 1750). However, it has a strong absorption potential in the infrared part of the spectrum. Radiative forcing is 0.001 W/m². Its ozone depletion potential (ODP) is 0.