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Methane

From ChemWiki

Introduction

Methane is the simplest carbon hydrogen structure, and one of the most abundant ones found in nature, being widely produced by many types of livestock, and found in gasfields. It is a colourless, odourless gas, which has a tetrahedral shape, and a bond angle of 109.5°. The strength of the carbon hydrogen covalent bond in methane is among the strongest in all hydrocarbons. It can undergo several reactions, including combustion and halogenation.

Reactions of Methane

Combustion

Methane can undergo full or partial oxidation:

Partial:

Full:

3D structure of methane

Methane
Methane
General
Systematic name Methane
Other names Natural gas, marsh gas, firedamp
Molecular formula CH4
SMILES C
Molar mass 16
Appearance Colourless gas
CAS number 74-82-8
Properties
Density & phase 0.717 kg/m³ gas
Solubility in water 3.5 mg/100 ml (17°C)
Melting point 90.6 K
Boiling point 111.55 K
Structure
Molecular shape Tetrahedral
Coordination
geometry
tetrahedral
Dipole moment 0 D
Hazards
MSDS External MSDS
Main hazards Highly flammable
Flash point -188°C
R/S statement R: R12
S:(S2) S9 S16 S33

HOMO - LUMO Molecular Orbitals

Image obtained from this link

Effects on Global Warming

Methane has been shown to be a more potent greenhouse gas than carbon dioxide (it retains up to 20 times more heat that carbon dioxide), but at the moment it remains at a much lower level than carbon dioxide. However this could change as time goes on, as landfills, increased livestock production, coal mining and rice cultivation all contribute heavily to methane production, and with ever expanding populations the demand for these comodities will only increase, raising the production of methane.