Names | |
---|---|
Preferred IUPAC name 2-Methylbutane [1] | |
Other names Isopentane | |
Identifiers | |
3D model (JSmol) | |
1730723 | |
ChEBI | |
ChemSpider | |
ECHA InfoCard | 100.001.039 |
EC Number |
|
49318 | |
MeSH | isopentane |
PubChem CID | |
RTECS number |
|
UNII | |
UN number | 1265 |
CompTox Dashboard (EPA) | |
| |
| |
Properties | |
C5H12 | |
Molar mass | 72.151 g·mol−1 |
Appearance | Colorless liquid |
Odor | Gasoline-like |
Density | 616 mg mL−1 [2] |
Melting point | −161 to −159 °C; −258 to −254 °F; 112 to 114 K |
Boiling point | 27.8 to 28.2 °C; 81.9 to 82.7 °F; 300.9 to 301.3 K |
Vapor pressure | 76.992 kPa (at 20 °C) |
Henry's law constant (kH) | 7.2 nmol Pa−1 kg−1 |
UV-vis (λmax) | 192 nm |
Refractive index (nD) | 1.354 |
Viscosity | 0.214 cP (at 20 °C) |
Thermochemistry | |
Heat capacity (C) | 164.85 J K−1 mol−1 |
Std molar entropy (S⦵298) | 260.41 J K−1 mol−1 |
Std enthalpy of formation (ΔfH⦵298) | −179.1–−177.3 kJ mol−1 |
Std enthalpy of combustion (ΔcH⦵298) | ~ 3.3 MJ mol−1, 19,664 Btu/lb |
Hazards | |
GHS labelling: | |
Danger | |
H224, H301, H302, H305, H336, H411 | |
P210, P261, P273, P301+P310, P331 | |
NFPA 704 (fire diamond) | |
Flash point | −51 °C (−60 °F; 222 K) |
420 °C (788 °F; 693 K) | |
Explosive limits | 1.4–8.3% |
Related compounds | |
Related alkanes | |
Related compounds | 2-Ethyl-1-butanol |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). |
Isopentane, also called methylbutane or 2-methylbutane, is a branched-chain saturated hydrocarbon (an alkane) with five carbon atoms, with formula C
5H
12 or CH(CH
3)
2(C
2H
5).
Isopentane is a volatile and flammable liquid. It is one of three structural isomers with the molecular formula C5H12, the others being pentane (n-pentane) and neopentane (2,2-dimethylpropane).
Isopentane is commonly used in conjunction with liquid nitrogen to achieve a liquid bath temperature of −160 °C. Natural gas typically contains 1% or less isopentane, [3] but it is a significant component of natural gasoline. [4]
The traditional name isopentane was still retained in the 1993 IUPAC recommendations, [5] [6] but is no longer recommended according to the 2013 recommendations. [1] The preferred IUPAC name is the systematic name 2-methylbutane. An isopentyl group is a subset of the generic pentyl group. It has the chemical structure -CH3CH2CH(CH3)2.
Isopentane is used in a closed loop in geothermal power production to drive turbines. [7]
Isopentane is used, in conjunction with dry ice or liquid nitrogen, to freeze tissues for cryosectioning in histology. [8]
Isopentane is a major component (sometimes 30% or more) of natural gasoline, an analog of common petroleum-derived gasoline that is condensed from natural gas. [4] It has a substantially higher octane rating (RON 93.7) than n-pentane (61.7), and therefore there is interest in conversion from the latter. [9]
In organic chemistry, an alkane, or paraffin, is an acyclic saturated hydrocarbon. In other words, an alkane consists of hydrogen and carbon atoms arranged in a tree structure in which all the carbon–carbon bonds are single. Alkanes have the general chemical formula CnH2n+2. The alkanes range in complexity from the simplest case of methane, where n = 1, to arbitrarily large and complex molecules, like pentacontane or 6-ethyl-2-methyl-5-(1-methylethyl) octane, an isomer of tetradecane.
In organic chemistry, hydrocarbons are divided into two classes: aromatic compounds and aliphatic compounds. Aliphatic compounds can be saturated like hexane, or unsaturated, like hexene and hexyne. Open-chain compounds, whether straight or branched, and which contain no rings of any type, are always aliphatic. Cyclic compounds can be aliphatic if they are not aromatic.
Ethylene is a hydrocarbon which has the formula C2H4 or H2C=CH2. It is a colourless, flammable gas with a faint "sweet and musky" odour when pure. It is the simplest alkene.
In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. Hydrocarbons are examples of group 14 hydrides. Hydrocarbons are generally colourless and hydrophobic; their odor is usually faint, and may be similar to that of gasoline or lighter fluid. They occur in a diverse range of molecular structures and phases: they can be gases, liquids, low melting solids or polymers.
Isobutane, also known as i-butane, 2-methylpropane or methylpropane, is a chemical compound with molecular formula HC(CH3)3. It is an isomer of butane. Isobutane is a colorless, odorless gas. It is the simplest alkane with a tertiary carbon atom. Isobutane is used as a precursor molecule in the petrochemical industry, for example in the synthesis of isooctane.
In organic chemistry, an alkyl group is an alkane missing one hydrogen. The term alkyl is intentionally unspecific to include many possible substitutions. An acyclic alkyl has the general formula of −CnH2n+1. A cycloalkyl group is derived from a cycloalkane by removal of a hydrogen atom from a ring and has the general formula −CnH2n−1. Typically an alkyl is a part of a larger molecule. In structural formulae, the symbol R is used to designate a generic (unspecified) alkyl group. The smallest alkyl group is methyl, with the formula −CH3.
In chemical nomenclature, the IUPAC nomenclature of organic chemistry is a method of naming organic chemical compounds as recommended by the International Union of Pure and Applied Chemistry (IUPAC). It is published in the Nomenclature of Organic Chemistry. Ideally, every possible organic compound should have a name from which an unambiguous structural formula can be created. There is also an IUPAC nomenclature of inorganic chemistry.
Pentane is an organic compound with the formula C5H12—that is, an alkane with five carbon atoms. The term may refer to any of three structural isomers, or to a mixture of them: in the IUPAC nomenclature, however, pentane means exclusively the n-pentane isomer, in which case pentanes refers to a mixture of them; the other two are called isopentane (methylbutane) and neopentane (dimethylpropane). Cyclopentane is not an isomer of pentane because it has only 10 hydrogen atoms where pentane has 12.
In organic chemistry, a substituent is one or a group of atoms that replaces atoms, thereby becoming a moiety in the resultant (new) molecule.
Pyrrolidine, also known as tetrahydropyrrole, is an organic compound with the molecular formula (CH2)4NH. It is a cyclic secondary amine, also classified as a saturated heterocycle. It is a colourless liquid that is miscible with water and most organic solvents. It has a characteristic odor that has been described as "ammoniacal, fishy, shellfish-like". In addition to pyrrolidine itself, many substituted pyrrolidines are known.
Neopentane, also called 2,2-dimethylpropane, is a double-branched-chain alkane with five carbon atoms. Neopentane is a flammable gas at room temperature and pressure which can condense into a highly volatile liquid on a cold day, in an ice bath, or when compressed to a higher pressure.
Pentyl is a five-carbon alkyl group or substituent with chemical formula -C5H11. It is the substituent form of the alkane pentane.
A chemical nomenclature is a set of rules to generate systematic names for chemical compounds. The nomenclature used most frequently worldwide is the one created and developed by the International Union of Pure and Applied Chemistry (IUPAC).
Natural gasoline is a liquid hydrocarbon mixture condensed from natural gas, similar to common gasoline (petrol) derived from petroleum.
Pyrazolidine is a heterocyclic compound. It is a liquid that is stable in air, but it is hygroscopic.
In chemical nomenclature, a preferred IUPAC name (PIN) is a unique name, assigned to a chemical substance and preferred among all possible names generated by IUPAC nomenclature. The "preferred IUPAC nomenclature" provides a set of rules for choosing between multiple possibilities in situations where it is important to decide on a unique name. It is intended for use in legal and regulatory situations.
Propadiene or allene is the organic compound with the formula H2C=C=CH2. It is the simplest allene, i.e. a compound with two adjacent carbon double bonds. As a constituent of MAPP gas, it has been used as a fuel for specialized welding.
Perfluoropentane (PFP) or dodecafluoropentane; also known as Perflenapent (INN/USAN) is a fluorocarbon, the fluorinated analogue of pentane. It is a liquid that boils at slightly over room temperature.
Indolizine is an heterocyclic compound with the formula C8H7N). It is an uncommon isomer of indole with the nitrogen located at a ring fusion position. The saturated analogs are indolizidine, which are found in a variety of alkaloids such as swainsonine.
Butane or n-butane is an alkane with the formula C4H10. Butane is a highly flammable, colorless, easily liquefied gas that quickly vaporizes at room temperature and pressure. The name butane comes from the root but- (from butyric acid, named after the Greek word for butter) and the suffix -ane. It was discovered in crude petroleum in 1864 by Edmund Ronalds, who was the first to describe its properties, and commercialized by Walter O. Snelling in the early 1910s.
The names 'isobutane', 'isopentane' and 'neopentane' are no longer recommended.