AskDefine | Define hexane

Dictionary Definition

hexane n : a colorless flammable liquid alkane derived from petroleum and used as a solvent

User Contributed Dictionary

English

Etymology

From hex + -ane.

Noun

  1. Any of five isomeric aliphatic hydrocarbons, C6H14. They are colorless, volatile liquids.

Derived terms

Translations

aliphatic hydrocarbon: C6H14
  • Finnish: heksaani
  • French: hexane
  • Italian: esano
  • Swedish: hexan

French

Noun

fr-noun m

Extensive Definition

Hexane is an alkane hydrocarbon with the chemical formula CH3(CH2)4CH3. The "hex" prefix refers to its six carbons, while the "ane" ending indicates that its carbons are connected by single bonds. Hexane isomers are largely unreactive, and are frequently used as an inert solvent in organic reactions because they are very non-polar. They are also common constituents of gasoline and glues used for shoes, leather products and roofing. Additionally, it is used in solvents to extract oils for cooking and as a cleansing agent for shoe, furniture and textile manufacturing. In laboratories, hexane is used to extract oil and grease from water and soil before determination by gravimetric analysis or gas chromatography.

Isomers

Hexane has five isomers:
  • Hexane, CH3CH2CH2CH2CH2CH3, a straight chain of six carbon at* 2-Methylpentane (Isohexane)oms.
, CH3CH(CH3)CH2CH2CH3, a five-carbon chain with one methyl branch on the Second.
  • 3-Methylpentane, CH3CH2CH(CH3)CH2CH3, a five-carbon chain with one methyl branch on the third.
  • 2,3-Dimethylbutane, CH3CH(CH3)CH(CH3)CH3, a four-carbon chain with one methyl branch on the second and third.
  • 2,2-Dimethylbutane, CH3C(CH3)2CH2CH3, a four-carbon chain with two methyl branches on the second.

Production

Hexane is produced by the refining of crude oil. The exact composition of the fraction depends largely on the source of the oil (crude or reformed) and the constraints of the refining. The industrial product (usually around 50% by weight of the straight-chain isomer) is the fraction boiling at 65–70 °C.

Toxicity

The acute toxicity of hexane is relatively low, although it is a mild anesthetic. Inhalation of high concentrations produces first a state of mild euphoria, followed by somnolence with headaches and nausea.
Chronic intoxication from hexane has been observed in recreational solvent abusers and in workers in the shoe manufacturing, furniture restoration and automobile construction industries. The initial symptoms are tingling and cramps in the arms and legs, followed by general muscular weakness. In severe cases, atrophy of the skeletal muscles is observed, along with a loss of coordination and problems of vision.
Similar symptoms are observed in animal models. They are associated with a degeneration of the peripheral nervous system (and eventually the central nervous system), starting with the distal portions of the longer and wider nerve axons. The toxicity is not due to hexane itself but to one of its metabolites, hexane-2,5-dione. It is believed that this reacts with the amino group of the side chain of lysine residues in proteins, causing cross-linking and a loss of protein function.
The effects of hexane poisoning in humans are uncertain. In 1994, n-hexane was included in the list of chemicals on the Toxic Release Inventory (TRI). In the latter part of the 20th and early part of the 21st centuries, a number of explosions have been attributed to the combustion of hexane gas. In 2001, the U.S. Environmental Protection Agency issued regulations on the control of emissions of hexane gas due to its potential carcinogenic properties and environmental concerns.

References

  • Institut national de recherche et de sécurité. (2005). "Hexane". Fiche toxicologique n° 113, 8pp. (in French)
hexane in Arabic: هكسان
hexane in Bosnian: Heksan
hexane in Catalan: Hexà
hexane in Danish: Hexan
hexane in German: Hexan
hexane in Estonian: Heksaan
hexane in Spanish: Hexano
hexane in Esperanto: Heksano
hexane in French: Hexane
hexane in Indonesian: Heksana
hexane in Italian: Esano
hexane in Hebrew: הקסאן
hexane in Kurdish: Heksan
hexane in Latvian: Heksāns
hexane in Hungarian: Hexán
hexane in Dutch: Hexaan
hexane in Japanese: ヘキサン
hexane in Norwegian: Heksan
hexane in Polish: Heksan
hexane in Portuguese: Hexano
hexane in Russian: Гексан
hexane in Serbian: Хексан
hexane in Finnish: Heksaani
hexane in Swedish: Hexan
hexane in Tamil: ஹெக்சேன்
hexane in Vietnamese: Hexan
hexane in Chinese: 己烷
Privacy Policy, About Us, Terms and Conditions, Contact Us
Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2
Material from Wikipedia, Wiktionary, Dict
Valid HTML 4.01 Strict, Valid CSS Level 2.1