Methane
Methane is an organic compound with the chemical formula CH4. It is an alkane with one carbon atom. It is often found as the main part of natural gas. Methane is a greenhouse gas[3][4] 23 times more effective than carbon dioxide. It is also less stable and slowly oxidates by oxygen to carbon dioxide and water.
| Names | |
|---|---|
| Preferred IUPAC name
Methane[1] | |
| Systematic IUPAC name
Carbane (never recommended[1]) | |
Other names
| |
| Identifiers | |
| CAS number | |
| PubChem | |
| EC number | 200-812-7 |
| KEGG | C01438 |
| MeSH | |
| ChEBI | CHEBI:16183 |
| RTECS number | PA1490000 |
| SMILES | C |
| Beilstein Reference | 1718732 |
| Gmelin Reference | 59 |
| 3DMet | B01453 |
| Properties | |
| Molecular formula | CH4 |
| Molar mass | 16.04 g mol-1 |
| Appearance | Colorless gas |
| Odor | Odorless |
| Density |
|
| Melting point |
-182 °C, 90.7 K, -296 °F |
| Boiling point | |
| Solubility in water | 22.7 mg·L−1 |
| Solubility | Soluble in ethanol, diethyl ether, benzene, toluene, methanol, acetone and insoluble in water |
| log P | 1.09 |
| kH | 14 nmol·Pa−1·kg−1 |
| −12.2×10−6 cm3·mol−1 | |
| Structure | |
| Td | |
| Molecular shape | Tetrahedron |
| Dipole moment | 0 D |
| Thermochemistry | |
| Std enthalpy of formation ΔfH |
−74.87 kJ·mol−1 |
| Std enthalpy of combustion ΔcH |
−891.1 to −890.3 kJ·mol−1 |
| Standard molar entropy S |
186.25 J·(K·mol)−1 |
| Specific heat capacity, C | 35.69 J·(K·mol)−1 |
| Hazards | |
| NFPA 704 |
4
2
0
|
| Explosive limits | 4.4–17% |
It is a gas at 25 degrees Celsius at standard atmosphere (a specific pressure).
Uses
Methane is used in gas taps in places such as kitchens, chemistry classrooms, laboratories and more, as it burns very easily because of its simple molecular structure.
Molecular structure
Methane's molecular structure is very simple. It is a single carbon atom surrounded by four hydrogen atoms.
Production
Methane can be made by many chemical ways, but usually is found in natural gas and is obtained by fractional distillation, after it has become liquid.
Methane Media
Covalently bonded hydrogen and carbon in a molecule of methane.
Methane bubbles can be burned on a wet hand without injury.
Global methane budget (2017). Shows natural sources and sinks (green), anthropogenic sources (orange), and mixed natural and anthropogenic sources (hatched orange-green for 'biomass and biofuel burning').
Abiotic sources of methane[example needed] have been found in more than 20 countries and in several deep ocean regions so far.
Testing Australian sheep for exhaled methane production (2001), CSIRO
This image represents a ruminant, specifically a sheep, producing methane in the four stages of hydrolysis, acidogenesis, acetogenesis, and methanogenesis.
This diagram shows a method for producing methane sustainably. See: electrolysis, sabatier reaction
Bar graph of sources global of methane emissions. Energy sector emissions are from the Global Methane Tracker for 2021; non-energy sector emissions are the average of estimates available from UNFCCC, CAIT, EDGAR and CEDS for 2018 or 2019. Natural sources and biomass burning are top-down median estimates and bottom-up median estimates respectively from the Global Methane Budget for 2017.
An International Energy Agency graphic showing the potential of various emission reduction policies for addressing global methane emissions.
References
- ↑ 1.0 1.1 Nomenclature of Organic Chemistry : IUPAC Recommendations and Preferred Names 2013 (Blue Book) (2014). Cambridge: The Royal Society of Chemistry. p. 3–4. ISBN 978-0-85404-182-4. doi:10.1039/9781849733069-FP001.
- ↑ Gas Encyclopedia. Retrieved November 7, 2013.
- ↑ White House Unveils Plans to Cut Methane Emissions March 28, 2014 New York Times
- ↑ Brad Plumer. Methane levels in the atmosphere are now rising at their fastest pace in decades; It's a big problem for climate change. (December 12, 2016)Vox.com. Retrieved 18 December 2016.