Properties

General Structure formula of Methane, typeset with PPCHTeX startchemical chemical[ONE,SD1,SB4,BB2,SB7,Z01247][C,H,H,H,H] stopchemical File links The following pages link to this file: Methane User:Sverdrup/Images Categories: GFDL images ...
Name	Methane
Lewis Structure: Categories: Chemistry stubs | Chemistry ... H | H-C-H | H
Chemical formula	CH4
Formula weight	16.04 u
Synonyms	Marsh gas; Methyl hydride
CAS number	74-82-8
Phase behavior A chemical formula (also called molecular formula) is a concise way of expressing information about the atoms that constitute a particular chemical compound. ... General Name, Symbol, Number carbon, C, 6 Chemical series nonmetals Group, Period, Block 14, 2, p Appearance black (graphite) colorless (diamond) Atomic mass 12. ... General Name, Symbol, Number hydrogen, H, 1 Chemical series nonmetals Group, Period, Block 1, 1, s Appearance colorless Atomic mass 1. ... ... The atomic mass unit (amu), unified atomic mass unit (u), or dalton (Da), is a small unit of mass used to express atomic masses and molecular masses. ... CAS registry numbers are unique numerical identifiers for chemical compounds, polymers, biological sequences and alloys. ...
Melting point	90.6 K (-182.5°C)
Boiling point	111.55 K (-161.6°C)
Triple point	90.67 K (-182.48°C) 0.117 bar
Critical point	190.6 K (-82.6°C) 46 bar
ΔfusH	1.1 kJ/mol
ΔvapH	8.17 kJ/mol
Gas properties The melting point of a solid is the temperature at which it changes state from solid to liquid. ... The kelvin (symbol: K) is the SI unit of temperature, and is one of the seven SI base units. ... The degree Celsius (°C) is a unit of temperature named after the Swedish astronomer Anders Celsius (1701–1744), who first proposed a similar system in 1742. ... The boiling point of a substance is the temperature at which it can change state from a liquid to a gas throughout the bulk of the liquid. ... In physics, the triple point of a substance is the temperature and pressure at which three phases (gas, liquid, and solid) of that substance may coexist in thermodynamic equilibrium. ... The bar is a measurement unit of pressure, equal to 1,000,000 dynes per square centimetre (baryes), or 100,000 newtons per square metre (pascals). ... Chemistry In chemistry, a critical point is the conditions ( temperature, pressure) at which the liquid state of the matter ceases to exist. ... The bar is a measurement unit of pressure, equal to 1,000,000 dynes per square centimetre (baryes), or 100,000 newtons per square metre (pascals). ... This article is in need of attention. ... The heat of vaporization is a physical property of substances. ...
ΔfH0gas	-74.87 kJ/mol
ΔfG0gas	-50.828 kJ/mol
S0gas	188 J/mol·K
Cp	35.69 J/mol·K
Safety The standard enthalpy of formation of a compound is the change of enthalpy that accompanies the formation of 1 mole of that substance from its component elements, at their standard states (the most stable form of the element at 25 degrees Celsius and 100 kilopascals). ... In chemistry, the standard molar entropy is the entropy content of one mole of substance, under conditions of standard temperature and pressure. ... Heat capacity (abbreviated Cth or just C, also called thermal capacity) is the ability of matter to store heat. ...
Acute effects	Asphyxia; in severe cases unconsciousness, cardiac arrest or CNS injury. The compound is transported as a cryogenic liquid, exposure to this will obviously cause frostbite.
Chronic effects	???
Flash point	-188°C
Autoignition temperature	600°C
Explosive limits	5-15%
More info The flashpoint of a fuel is the lowest temperature at which it can form an ignitable mix with air. ... Categories: Pages needing attention | Chemistry stubs | Chemistry ... The explosive limit of a gas or a vapour, is the limiting concentration (in air) that is needed for the gas to ignite and explode. ...
Properties	NIST WebBook
MSDS	Hazardous Chemical Database
SI units were used where possible. Unless otherwise stated, standard conditions were used. A material safety data sheet or MSDS is a form containing data regarding the properties of a particular substance. ... The International System of Units (abbreviated SI from the French phrase, Système International dUnités) is the most widely used system of units. ... Temperature and air pressure can vary from one place to another on the Earth, and can also vary in the same place with time. ... Disclaimer and references This page refers to the data given in chemical compound property tables. ...

The simplest hydrocarbon, methane, is a gas with a chemical formula of CH₄. Pure methane is odorless, but when used commercially is usually mixed with small quantities of strongly-smelling sulfur compounds such as ethyl mercaptan to enable the detection of leaks. In chemistry, a hydrocarbon is any chemical compounds that consists only of carbon (C) and hydrogen (H). ... Gas (actually, as), the GNU assembler, is the default GCC back-end. ... A chemical formula (also called molecular formula) is a concise way of expressing information about the atoms that constitute a particular chemical compound. ... General Name, Symbol, Number carbon, C, 6 Chemical series nonmetals Group, Period, Block 14, 2, p Appearance black (graphite) colorless (diamond) Atomic mass 12. ... General Name, Symbol, Number hydrogen, H, 1 Chemical series nonmetals Group, Period, Block 1, 1, s Appearance colorless Atomic mass 1. ... Odor receptors on the antennae of a Luna moth An odor (American English) or odour (Commonwealth English) is the object of perception of the sense of olfaction. ... General Name, Symbol, Number sulfur, S, 16 Chemical series nonmetals Group, Period, Block 16, 3, p Appearance lemon yellow Atomic mass 32. ... In chemistry, thiols (formerly known as mercaptans) are those compounds which contain the thiol group -SH attached to a carbon atom. ...

A principal component of natural gas, methane is a significant fuel. Burning one molecule of methane in the presence of oxygen releases one molecule of CO₂ (carbon dioxide) and two molecules of H₂O (water): Natural gas rig Natural gas (commonly refered to as gas in many countries) is a gaseous fossil fuel consisting primarily of methane. ... For the workstation, see SGI Fuel. ... General Name, Symbol, Number oxygen, O, 8 Chemical series nonmetals Group, Period, Block 16, 2, p Appearance colorless Atomic mass 15. ... Carbon dioxide is an atmospheric gas composed of one carbon and two oxygen atoms. ... Water (from the Old English word wæter) is a colorless, tasteless, and odorless substance that is essential to all known forms of life and is known also as the most universal solvent. ...

CH₄ + 2O₂ → CO₂ + 2H₂O

Methane is a greenhouse gas with a global warming potential of 21. Increasing CO2 levels Greenhouse gases (GHG) are gaseous components of the atmosphere that contribute to the greenhouse effect. ... Global warming potential (GWP) is a measure of how much a given mass of greenhouse gas is estimated to contribute to global warming. ...

Sources of methane

Principal methane sources are

• decomposition of organic wastes
• natural sources (marshes): 23 %
• mineral fuel extraction: 20 %, see Coal bed methane extraction

Methane is extracted from geological deposits as a mineral fuel which is associated with other hydrocarbon fuels. Waste inside a trash can Waste is unwanted or undesired material left over after the completion of a process. ... This article is about marsh, a type of wetland. ... Coal rail cars in Ashtabula, Ohio Fossil fuels, also known as mineral fuels, are hydrocarbon-containing natural resources such as coal, petroleum and natural gas. ... Coal bed methane extraction is a method for extracting methane from a coal deposit. ... In chemistry, a hydrocarbon is any chemical compounds that consists only of carbon (C) and hydrogen (H). ...

• the processes of digestion in animals (cattle): 17 %
• bacteria found in rice plantations: 12 %
• biomass anaerobic heating or combustion

60% of the world emissions are from sources affected by humans. They come primarily from agricultural and other human activities. During the past 200 years, the concentration of this gas in the atmosphere doubled, passing from 0.8 to 1.7 ppm. Digestion is the process whereby a biological entity processes a substance, in order to chemically convert the substance into nutrients. ... Binomial name Bos taurus Linnaeus, 1758 Rainbow arching over a paddock of cattle Cattle are domesticated ungulates, a member of the subfamily Bovinae of the family Bovidae. ... Phyla/Divisions Actinobacteria Aquificae Bacteroidetes/Chlorobi Chlamydiae/Verrucomicrobia Chloroflexi Chrysiogenetes Cyanobacteria Deferribacteres Deinococcus-Thermus Dictyoglomi Fibrobacteres/Acidobacteria Firmicutes Fusobacteria Gemmatimonadetes Nitrospirae Omnibacteria Planctomycetes Proteobacteria Spirochaetes Thermodesulfobacteria Thermomicrobia Thermotogae Bacteria (singular, bacterium) are a major group of living organisms. ... Species References ITIS 41975 2002-09-22 Rice (genus Oryza) is a plant of the grass family which is a dietary staple of more than half of the worlds human population. ... Biomass is organic non-fossil material, collectively. ... Anaerobic is a technical word which literally means without air. ... The word emission generally means sending something out. ...

Methane is also classified as a biogas because it can be created by the (anaerobic) decomposition of certain organic matters. Biogas typically refers to methane produced by the fermentation of organic matter such as manure under anaerobic conditions. ... Anaerobic is a technical word which literally means without air. ... Rotting fruit Decomposition is the reduction of bodies and other formerly living organisms into simpler forms of matter and, most particularly, to the fate of the human body after death. ... Organic has several meanings and related topics. ...

• Industrial sources

Methane can be created and used industrially, and perhaps in nature, by chemical reactions such as the Sabatier process, Fischer-Tropsch process, and steam reforming. Similar gases and materials are often present in geologic and volcanic processes. The Sabatier process involves the reaction of hydrogen with carbon dioxide at elevated temperatures and pressures in the presence of a nickel catalyst to produce methane and water. ... The Fischer-Tropsch process is a catalyzed chemical reaction in which carbon dioxide, carbon monoxide and methane are converted into liquid hydrocarbons of various forms. ... Steam reforming is a method of producing hydrogen. ... A volcano is a geological landform (usually a mountain) where magma (rock of the earths interior made molten or liquid by high pressure and temperature) erupts through the surface of the planet. ...

• At high pressures, such as are found on the bottom of the ocean, methane forms a solid clathrate with water. An unknown but possibly very large quantity of methane is trapped in this form in ocean sediments. The sudden release of large volumes of methane from such sediments into the atmosphere has been suggested as a possible cause for rapid global warming events in the earth's distant past, such as the Paleocene-Eocene thermal maximum of 55 million years ago.

A clathrate or clathrate compound is a chemical substance consisting of a Greek klethra, meaning bars (in the sense of a lattice). ... Global mean surface temperatures 1856-2004 Mean temperature anomalies during the period 1995 to 2004 with respect to the average temperatures from 1940 to 1980 Global warming is a term used to describe an increase over time of the average temperature of Earths atmosphere and oceans. ... The end of the Paleocene (55. ...

Reactions of methane

• Combustion

In the combustion of methane several steps are involved: Combustion or burning is an exothermic reaction between a substance (the fuel) and a gas (the oxidizer) to release heat. ...

Methane forms to a methyl radical (CH₃), which reacts to formaldehyde (HCHO or H₂CO). The formaldehyde reacts to a formal radical (HCO), which then forms carbon monoxide (CO). The process is called oxidative pyrolysis: In chemistry a methyl-group is a hydrophobic Alkyl functional group which is derived from methane (CH4). ... REACT or react can be:- Radio Emergency Associated Communication Teams (an emergency service who monitor the CB radio) REACT belt (a restraint device) A chemical or nuclear or other process as in reaction. ... The chemical compound formaldehyde (also known as methanal), is a gas with a strong pungent smell. ... Radical is derived from the Latin word radix, which means root. In various fields of endeavor, it can mean: Sciences in chemistry, either an atom or molecule with at least one unpaired electron, or a group of atoms, charged or uncharged, that act as a single entity in reaction. ... Carbon monoxide, chemical formula CO, is a colourless, odourless, flammable and highly toxic gas. ... Pyrolysis is formally defined as chemical decomposition of organic materials by heating in the absence of oxygen. ...

CH₄ + O₂ → CO + H₂ + H₂O

Following oxidative pyrolysis, the H₂ oxidizes, forming H₂O, replenishing the active species, and releasing heat. This occurs very quickly, usually in less than a millisecond. A millisecond is an SI-derived unit of time, equal to one thousandth of a second. ...

H₂ + ½ O₂ → H₂O

Finally, the CO oxidizes, forming CO₂ and releasing more heat. This process is generally slower than the other chemical steps, and typically requires a few to several milliseconds to occur.

CO + ½ O₂ → CO₂

• Hydrogen activation

The strength of the carbon-hydrogen covalent bond in methane is among the strongest in all hydrocarbons, and thus its use as a chemical feedstock is limited. The search for catalysts which can facilitate C-H bond activation in methane and other low alkanes is an area of research with considerable industrial significance. General Name, Symbol, Number carbon, C, 6 Chemical series nonmetals Group, Period, Block 14, 2, p Appearance black (graphite) colorless (diamond) Atomic mass 12. ... General Name, Symbol, Number hydrogen, H, 1 Chemical series nonmetals Group, Period, Block 1, 1, s Appearance colorless Atomic mass 1. ... Covalently bonded hydrogen and carbon in a molecule of methane. ... A feedstock is a petrochemical used as a raw material to be fed into a machine or processing plant. ... A catalyst (Greek: καταλύτης, catalytis) is a substance that accelerates the rate of a chemical reaction, at some temperature, but without itself being transformed or consumed by the reaction (see also catalysis). ... An alkane in organic chemistry is a saturated hydrocarbon, that is, a hydrocarbon in which the molecule has the maximum possible number of hydrogen atoms and so has no double bonds. ...

• Halogenation

In chemistry, halogenation is a chemical reaction that replaces a hydrogen atom with a halogen atom. ...

Methane not on Earth

Methane has been detected or is believed to exist in several locations of the solar system. It is believed to have been created by abiotic processes, with the possible exception of Mars. Mosaic of Solar System planets except Pluto, including Earths Moon (not to scale). ... Scientists have long speculated about the possibility of life on Mars, due to that planets proximity and similarity to Earth. ...

• Jupiter
• Mars
• Saturn
  • Iapetus
  • Titan
• Neptune
  • Triton
• Uranus
  • Ariel
  • Miranda
  • Oberon
  • Titania
  • Umbriel
• Comet Halley
• Comet Hyakutake

Traces of methane gas are present in the thin atmosphere of the Earth's Moon. Atmospheric characteristics Atmospheric pressure 70 kPa Hydrogen ~86% Helium ~14% Methane 0. ... Mars, with polar ice caps visible. ... Atmospheric characteristics Atmospheric pressure 140 kPa Hydrogen >93% Helium >5% Methane 0. ... Iapetus (eye-ap-i-tus, Greek Ιαπετός) (British spelling: Japetus) is the third-largest moon of Saturn (see: Saturns natural satellites), discovered by Giovanni Domenico Cassini in 1671. ... Titan (tye-tun, Greek Τιτάνας) is the largest moon of Saturn and the second largest moon in the solar system[1], after Jupiters moon Ganymede. ... Atmospheric characteristics Surface pressure ≫100 MPa Hydrogen - H2 80% ±3. ... Triton (trye-tun, Greek Τρίτων) is the planet Neptunes largest moon, discovered by William Lassell on 1846-10-10, just 17 days after the planet itself was discovered. ... Atmospheric characteristics Atmospheric pressure 120 kPa Hydrogen 83% Helium 15% Methane 1. ... Atmospheric pressure 0 kPa Ariel (AIR ee el) is a moon of Uranus discovered in 1851 by William Lassell. ... Miranda (mi-ran-da) is the smallest and innermost of Uranus major moons. ... Atmospheric pressure 0 kPa Oberon (O ber on) is the outermost of the major moons of the planet Uranus. ... Titania should not be confused with Titan, a moon of Saturn. ... Click for full description. ... Comet Halley as taken with the Halley Multicolor Camera on the ESA Giotto mission. ... Comet Hyakutake, the Great Comet of 1996 Comet Hyakutake (pronounced /ħʝakutake/ or /ħʃakutake/; formally designated C/1996 B2) was a comet that was discovered in January 1996, passed very close to the Earth in March of that year, and was dubbed The Great Comet of 1996. ... Crust composition Oxygen 43% Silicon 21% Aluminium 10% Calcium 9% Iron 9% Magnesium 5% Titanium 2% Nickel 0. ...

Methane has also been detected in interstellar clouds. Interstellar cloud is the generic name given to accumulations of gas and dust in our galaxy. ...

Units of measure

• One cubic meter (m³) at normal pressure has a mass of 717 grams.

See also

• alkane, a type of hydrocarbon of which methane is simplest member.
• methane clathrate, form of water ice which contains methane.
• methanogen, archaea that produce methane as a metabolic by-product.
• methanogenesis, the formation of methane by microbes.
• methanotroph, bacteria that are able to grow using methane as their only source of carbon and energy.
• methyl group, a functional group similar to methane

An alkane in organic chemistry is a saturated hydrocarbon, that is, a hydrocarbon in which the molecule has the maximum possible number of hydrogen atoms and so has no double bonds. ... In chemistry, a hydrocarbon is any chemical compounds that consists only of carbon (C) and hydrogen (H). ... Burning ice. Methane released by heating burns, water drips. ... Methanogens are Archaea that produce methane as a metabolic by-product. ... Phyla / Classes Phylum Crenarchaeota Phylum Euryarchaeota     Halobacteria     Methanobacteria     Methanococci     Methanopyri     Archaeoglobi     Thermoplasmata     Thermococci Phylum Korarchaeota Phylum Nanoarchaeota The Archaea are a major group of prokaryotes. ... Methanogenesis is the formation of methane by microbes. ... A microorganism or microbe is an organism that is so small that it is microscopic (invisible to the naked eye). ... Methanotrophs are bacteria that are able to grow using methane as their only source of carbon and energy. ... Phyla/Divisions Actinobacteria Aquificae Bacteroidetes/Chlorobi Chlamydiae/Verrucomicrobia Chloroflexi Chrysiogenetes Cyanobacteria Deferribacteres Deinococcus-Thermus Dictyoglomi Fibrobacteres/Acidobacteria Firmicutes Fusobacteria Gemmatimonadetes Nitrospirae Omnibacteria Planctomycetes Proteobacteria Spirochaetes Thermodesulfobacteria Thermomicrobia Thermotogae Bacteria is also the fictional name of a warring nation under Benzino Napaloni as dictator, in the 1940 film The Great Dictator... In chemistry a methyl-group is a hydrophobic Alkyl functional group which is derived from methane (CH4). ...

External links

• Methane Hydrates