Methane

Properties, data and information sources.

Contents

Methane is an organic chemical compound from the class of hydrocarbons, which is assigned to the groups of alkanes and parent hydrides.

Names and Identifiers

Name
Methane

Formula
CH₄

Molar mass
16.043 (g/mol)

CAS registry number
74-82-8

EC number EINECS
200-812-7

InChI Key
VNWKTOKETHGBQD-UHFFFAOYSA-N

Other names, synonyms
Carbon tetrahydride; Carburetted hydrogen; Hydrogen carbide; Marsh gas; Methyl hydride; Carbane; Biogas; Fire Damp

Latin name
Methanum

Trade names; preparations
R-50; Gaz combustible HEN; HP Fuelgas ET

Chemical formulas

Molecular formula and structural formula of Methane:

CH₄

M_r = 16.043 g/mol
SMILES: C

Data and Properties

Under standard conditions, pure methane is a colorless, tasteless and odorless gas that burns in air with a pale, dimly glowing flame.

Methane is sold as a compressed gas under high pressure (200 bar) in corresponding pressure vessels (Compressed Natural Gas, CNG); the jacket of the gas cylinders is red (flammable).

solubility:
+ Soluble in diethyl ether, ethanol, benzene, methanol, toluene.
- Practically insoluble in water (24.4 mg gas per liter at 25 °C); slightly soluble in acetone.
partition coefficient logPOW = 1.09.

melting point
-182.65 °C

boiling point
-161.65 °C

flash point
-188 °C

ignition temperature
536.85 °C

density
0.657 kg cm^-3 at 20 °C

0.42 g cm^-3 (flüssig. am Siedepunkt)

pK_a value
pK_1a = 48

surface tension
0.014 N/m at -161 °C

refractive index
n_D = 1.000444 at 0 °C

standard enthalpy of formation
-74.6 kJ/mol [g] at 25 °C

standard entropie
186.3 J/(mol K) at 25 °C

Gibbs free energy
-50.5 kJ/mol

enthalpy of vaporization
8.17 kJ/mol

melting enthalpy
1.1 kJ/mol

enthalpy of combustion
-890.8 kJ/mol

heat capacity
35.69 J/(mol K)

calorific value
35.89 MJ m^-3
50.013 MJ kg^-1

critical points
T_c = -82.59 °C
p_c = 4.599 MPa
ρ_c = 562.2 kg m^-3
V_c = 98.60 cm³/mol

triple point
-182.48 °C / 0.117 bar

dipole moment
0 D

ionization energy
12.51 eV

magnetic susceptibility χ
-17.4 × 10^-6 cm³ mol^-1

crystal structure:
Methane forms plastic crystals (methane I), i.e. the H atoms in the solid are not bound to specific lattice sites: cubic, space group Fm3m, No. 225.

Methane - Solubility in Water

Spectroscopic data:

SPLASH (mass spectra)
splash10-014i-9000000000-42e2bf163f3e1178d2b7

MoNA Mass Bank of North America (mass spectrum)
VNWKTOKETHGBQD-UHFFFAOYSA-N

SpectraBase (NMR, IR, FTIR, Raman, UV-Vis, MS ... spectra)
EkUAlGqAVkW

NIST IR-Spektrum
Methane

Human Metabolome Database (GC-MS, LC-MS/MS spectra, NMR)
HMDB0002714

Calculated NMR spectrum (Predict Spectra via NMRDB)
¹H NMR Spektrum, ¹³C NMR Spektrum.

Percentage and isotopic composition:

Mass-related elemental composition and isotope proportions of the compound Methane - CH₄ - calculated based on molecular mass.

Symbol
Element ENumber x
of atoms E_xData of the element
and isotopes *Percentages
of isotopesPercentage of
E_x in formula massC
Carbon1ΣA_r = 12.011 u
¹²C: 12 u [98,94 %]
¹³C: 13.00335 u [1,06 %]
¹⁴C: 14.00324 u [<< 1 %]
¹²C: 74.07395 %
¹³C: 0.7936 %
¹⁴C: trace
74.8675 %H
Hydrogen4 A_r = 1.008 u
ΣA_r = 4.032 u
³H: 3.01605 u [<< 1 %]
¹H: 1.00783 u [99,99 %]
²H: 2.0141 u [0,01 %]
³H: trace
¹H: 25.12994 %
²H: 0.00251 %
25.1325 %

*) The third column lists the atomic masses or isotope masses of the elements involved and - in square brackets - the natural isotope composition.

More calculated data

The molar mass is M = 16.043 grams per mole.

The amount of substance in one kilogram of the substance is n = 62.332 mol.

The amount of substance in one gram of the substance is n = 0.062 mol.

Monoisotopic mass: 16.0313001288 Da - related to ¹²C¹H₄.

Hazard warnings according to GHS

(General information without guarantee of accuracy and completeness! The information does not replace the chemical safety data sheet or a risk assessment, but rather provides a general overview of the risk posed by the hazardous substance.

Signal word: Danger

GHS hazard statements (H phrases):

H220
Extremely flammable gas

Methane forms explosive mixtures with air in a range of 4.4 to 16.5 vol.% CH₄.

Labeling in the EU: See ECHA Substance Infocard 100.000.739.

For toxicology and occupational safety when handling Methane as well as measures to be taken in case of danger, see: Hazardous Substances Information System GESTIS, ZVG-Nr. 010000.

International Chemical Safety Card ICSC (SDS, MSDS): See ICSC: 0291.

External Sources

PubChem:ID 297ChemSpider:ID 291Kegg database DBGET:ID C01438UNII of the FDA (USA):Unique Ingredient Identifier OP0UW79H66EPA CompTox Chemicals Dashboard:DTXSID8025545Other CAS RN:131452-56-7 (also used, outdated or deleted registration numbers)

Manufacturers and Sources of Supply

The table below lists producers and suppliers of Methane as a commercial chemical for laboratories, research, industry and production with the corresponding contact details.

Literature Sources

[0] - Specialist and research articles in scientific journals via PubMed: Methane.

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Last update: 2024-10-10

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