Copyright © Philip M. Parker, INSEAD. Terms of Use.
Definition: Benzene |
BenzeneNoun1. A colorless liquid hydrocarbon; highly inflammable; carcinogenic. Source: WordNet 1.7.1 Copyright © 2001 by Princeton University. All rights reserved. |
Note: Benzene \Ben"zene\, noun. [From Benzoin.]. (Websters 1913) |
| Domain | Definitions |
Chemical Industry | A colourless, volatile, flammable aromatic hydrocarbon liquid used as a solvant and as a fuel for some special types of reciprocating engines. Source: European Union. (references) |
Energy | A type of colorless liquid hydrocarbon that can be used as a motor fuel.Its chemical symbol is C6H6. (references) |
Health | Toxic, volatile, flammable liquid hydrocarbon biproduct of coal distillation. It is used as an industrial solvent in paints, varnishes, lacquer thinners, gasoline, etc. Benzene causes central nervous system damage acutely and bone marrow damage chronically and is carcinogenic. It was formerly used as parasiticide. (references) |
Public Administration | Aromatic liquid hydrocarbon got from coal and petroleum, used as solvent, fuel, and in manufactury of plastics(1). Source: European Union. (references) |
Source: compiled by the editor from various references; see credits. | |
(From Wikipedia, the free Encyclopedia)
The chemical compound benzene (C6H6) is a colorless, flammable, aromatic hydrocarbon, that is a known carcinogen. It boils at 80.1°C and solidifies at 5.5°C. Benzene has a heat of vaporization of 44.3 kJ/mol and a heat of fusion of 9.84 kJ/mol. Produced by hydrogen reduction of some allotropes of carbon, or from petroleum, it is used in the creation of drugs, plastics, gasoline, synthetic rubber, and dyes.
Other aromatic compounds created by the replacement of hydrogen atoms with methyl (CH3) groups are called the benzene series. If one hydrogen is replaced, the new chemical is called toluene, (C6H5CH3), from which trinitrotoluene (TNT) is derived. If two hydrogens are replaced it becomes xylene, (C6H4(CH3)2).
Replacement of the hydrogen atoms with other functional groups produces additional derivaties. A hydroxyl group (OH) produces phenol (C6H5OH), and additional nitration produces picric acid, or trinitrophenol. Replacement with an amino group (-NH2) produces aniline (C6H5(NH2))
Two or more rings may be joined together, as in naphthalene, anthracene, and phenanthrene. Other atoms, such as nitrogen, may be substituted for carbon atoms in the ring, as in pyridine (C5H5N) and pyrimidine (C4H4N2): in this case the ring is said to be a heterocyclic ring.
The formula of benzene (C6H6), caused a mystery for some time after its discovery, as no proposed structure could take account of all the bonds (Carbon usually forms four single bonds and hydrogen one).
The chemist Kekulé was the first to deduce the ring structure of benzene; after years of studying carbon bonding, benzene and related molecules, the solution to the benzene structure came to him in a dream of a snake eating its own tail. Upon waking was inspired to deduce the ring structure of benzene.
While his claims were well publicized and accepted, by the early 1920s Kekulé's biographer came to the conclusion that Kekulé's understanding of the tetravalent nature carbon bonding depended on the previous research of Archibald Scott Couper (1831-1892); further, the German Chemist Josef Loschmidt (1821-1895) had earlier posited a cyclic structure for benzene as early as 1862, although he had not actually proved this structure to be correct.
Benzene presents a problem, as to account for all the bonds, there must be alternating double carbon bonds:
However, all of the carbon-carbon bonds in benzene are of the same length, and it is known that a single bond is longer than a double bond. In addition, the bond length (the distance between the two bonded atoms) in benzene is greater than a double bond, but shorter than a single bond. There seems in effect to be a bond and a half between each carbon.
This is explained by electron delocalization. In order to picture this, we must consider the position of electrons in the bonds of benzene. The single bonds are formed with electrons orbiting in paths in line with this page. The double bonds consist of a single bond and another bond. This second bond has electrons orbiting in paths above and below the plane of this page at each bonded carbon atom. In the diagram below we take a side-view of this occurring:
The '-' denotes the single bond, and the '@'s denote the orbitals of the electrons forming the double bonds.
Being out of the plane of the atoms, these electrons can interact with each other freely, and become delocalised. This means that instead of being tied to one atom of carbon, they are shared by all six in the ring. Thus there are not enough to form double bonds on all the carbon atoms, but the atoms do strengthen all of the bonds on the ring equally.
What in effect is happening is that the structure exists as a superposition of the above forms, rather than either form individually. This type of structure is called a resonance hybrid.
To reflect the delocalised nature of the bonding, benzene is usually depicted as a circle inside a hexagon in chemical structure diagrams:
Benzene occurs sufficiently often as a component of organic molecules that there is a Unicode symbol to represent it; code 232C, ⌬
It is one of the components of the coal tars given off when coal in converted to coke. Up until World War II, this source of benzene was sufficient to meet world demand for the chemical. However, in the 1950's, increasing demand for benzene, especially for the growing plastics necessitated the production of benzene from petroleum. Today, most benzene comes from the petrochemical industry, with only a small fraction being produced from coal.
As a gasoline additive, benzene increases the octane rating and reduces knocking. As a result, gasoline once often contained several percent benzene, although in the 1950s tetraethyl lead replaced it as the most widely used antiknock additive. However, with the global phaseout of leaded gasoline, benzene has made a comeback as a gasoline additive in some nations. In the United States, concern over its negative health effects and the possibility of benzene entering the groundwater have led to stringent regulation of gasoline's benzene content. Many European nations, on the other hand, either do not regulate benzene in gasoline or allow significant quantities of it, and European gasoline formulations often contain 5% or more benzene.
By far the largest use of benzene is an intermediate to make other chemicals. The most widely produced derivatives of benzene are styrene, which is used to make polymers and plastics phenol for resins and adhesives (via cumene), and cyclohexane, which is used in Nylon manufacture. Smaller amounts of benzene are used to make some types of rubbers, lubricants, dyes, detergents, drugs, explosives and pesticides.
Breathing very high levels of benzene can result in death, while high levels can cause drowsiness, dizziness, rapid heart rate, headaches, tremors, confusion, and unconsciousness. Eating or drinking foods containing high levels of benzene can cause vomiting, irritation of the stomach, dizziness, sleepiness, convulsions, rapid heart rate, and death.
The major effect of benzene from long-term (365 days or longer) exposure is on the blood. Benzene causes harmful effects on the bone marrow and can cause a decrease in red blood cells leading to anemia. It can also cause excessive bleeding and can affect the immune system, increasing the chance for infection.
Some women who breathed high levels of benzene for many months had irregular menstrual periods and a decrease in the size of their ovaries. It is not known whether benzene exposure affects the developing fetus in pregnant women or fertility in men.
Animal studies have shown low birth weights, delayed bone formation, and bone marrow damage when pregnant animals breathed benzene.
The US Department of Health and Human Services (DHHS) has determined that benzene is a known human carcinogen. Long-term exposure to high levels of benzene in the air can cause leukemia, cancer of the blood-forming organs.
Several tests can show if you have been exposed to benzene. There is test for measuring benzene in the breath; this test must be done shortly after exposure. Benzene can also be measured in the blood; however, since benzene disappears rapidly from the blood, measurements are accurate only for recent exposures.
In the body, benzene is converted to products called metabolites. Certain metabolites can be measured in the urine. However, this test must be done shortly after exposure and is not a reliable indicator of how much benzene you have been exposed to, since the metabolites may be present in urine from other sources.
The US Environmental Protection Agency has set the maximum permissible level of benzene in drinking water at 0.005 milligrams per liter (0.005 mg/L). The EPA requires that spills or accidental releases into the environment of 10 pounds or more of benzene be reported to the EPA.
The US Occupational Safety and Health Administration (OSHA) has set a permissible exposure limit of 1 part of benzene per million parts of air (1 ppm) in the workplace during an 8-hour workday, 40-hour workweek.
Archibald Scott Couper, On a New Chemical Theory, Philosophical Magazine 16, 104-116 (1858)
Josef Loschmidt, Chemische Studien I, Carl Gerold's Sohn, Vienna (1861),
Josef Loschmidt, Chemische Studien I, Aldrich Chemical Co, Milwaukee (1989), catalog no. Z-18576-0, and (1913) catalog no. Z-18577-9Structure
@ @
C-C
@ @
Production
Benzene may result whenever carbon-rich materials undergo incomplete combustion. It is produced naturally in volcanoes and forest fires, and is also a component of cigarette smoke. Industrially, it is produced from either coal or petroleum. The steel industry 'cokes' coal. This coke is then 'cracked' to yield Benzene(63%), Toluene(14%) & Xylene(7%). Alternatively an Olefin plant will produce Benzene as a by-product of cracking naptha or gas oil.Uses
Prior to the 1920's, benzene was frequently used as an industrial solvent, especially for degreasing metal. As its toxicity became obvious, other solvents replaced benzene in application that directly exposed the user to benzene.Health effects
External links
References
Source: adapted by the editor from Wikipedia, the free encyclopedia under a copyleft GNU Free Documentation License (GFDL) from the article "Benzene."
Synonyms: BenzeneSynonyms: benzine (n), benzol (n). (additional references) |
| Context | Synonyms within Context (source: adapted from Roget's Thesaurus). |
Cleanness | Wash, lotion, detergent, cathartic, purgative; purifier; Verb: disinfectant; aperient; benzene, benzine benzol, benolin; bleaching powder, chloride of lime, dentifrice, deobstruent, laxative. |
| Source: adapted from Roget's Thesaurus. | |
| Domain | Title |
Books |
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Source: compiled by the editor from various references; see credits. | |
| Subject | Topic | Quote |
Health | Bone marrow damage - benzene (gasoline). (references) | |
Business | There is no domestic production of methanol, toluene, benzene or xylene. (references) | |
Economic History | France | Ten -percent growth for 2001 is expected, after two years of double-digit growth -- 14 percent in 1999 and 17 percent in 2000. A need for continuous automatic air ambient analyzers that monitor Volatile Organic Components (VOC), benzene, Polycyclical Aromatic Hydrocarbons (PAH) and heavy metals will also provide market opportunities in the near future. (references) |
Source: compiled by the editor from ICON Group International, Inc.; see credits. | ||
| "Benzene" is generally used as a noun (singular) -- approximately 95.54% of the time. "Benzene" is used about 112 times out of a sample of 100 million words spoken or written in English. Its rank is based on over 700,000 words used in the English language. Some parts-of-speech are not covered due to the samples used by the British National Corpus. (note: percents less than one-hundredth of one percent have been omitted) |
| Parts of Speech | Percent | Usage per 100 Million Words | Rank in English |
| Noun (singular) | 95.54% | 107 | 31,463 |
| Noun (proper) | 4.46% | 5 | 157,705 |
| Total | 100.00% | 112 | N/A |
Source: compiled by the editor from several corpora; see credits.
Expressions using "benzene": benzene formula ♦ Benzene nucleus ♦ Benzene ring ♦ dihydroxy benzene ♦ ethyl benzene ♦ methyl benzene ♦ vinyl benzene. Additional references. | |
| Hyphenated Usage | |
Beginning with "benzene": benzene-azo-benzene, benzene-diazo-chloride, benzene-like, benzene-sulphonic acid. | |
Ending with "benzene": benzene-azo-benzene, chloro-benzene, gamma-benzene. | |
| Source: compiled by the editor from various references; see credits. | |
| The following statistics estimate the number of searches per day across the major English-language search engines as identified by various trade publications. Hyperlinks lead to commercial use of the expression at Amazon.com. |
| Language | Translations for "benzene"; alternative meanings/domain in parentheses. | ||||||||||||||||||||||||||||||||||||||||||||||||||||
Afrikaan | benseen. (various references) | ||||||||||||||||||||||||||||||||||||||||||||||||||||
Albanian | benzol (benzol). (various references) | ||||||||||||||||||||||||||||||||||||||||||||||||||||
Arabic | البنزين, البنزول. (various references) | ||||||||||||||||||||||||||||||||||||||||||||||||||||
Bulgarian | бензол. (various references) | ||||||||||||||||||||||||||||||||||||||||||||||||||||
Chinese | 苯 . (various references) | ||||||||||||||||||||||||||||||||||||||||||||||||||||
Czech | benzen. (various references) | ||||||||||||||||||||||||||||||||||||||||||||||||||||
Danish | benzen (benzol, benzole). (various references) | ||||||||||||||||||||||||||||||||||||||||||||||||||||
Dutch | benzeen (benzol, benzole). (various references) | ||||||||||||||||||||||||||||||||||||||||||||||||||||
Esperanto | benzeno. (various references) | ||||||||||||||||||||||||||||||||||||||||||||||||||||
Finnish | bentseeni (benzol, benzole). (various references) | ||||||||||||||||||||||||||||||||||||||||||||||||||||
French | benzène (benzen, benzol, benzole). (various references) | ||||||||||||||||||||||||||||||||||||||||||||||||||||
German | Benzol (benzol, benzole, Benzoyl). (various references) | ||||||||||||||||||||||||||||||||||||||||||||||||||||
Greek | βενζόλιο (benzol, benzole). (various references) | ||||||||||||||||||||||||||||||||||||||||||||||||||||
Hebrew | ב זין (gas, gasoline, petrol). (various references) | ||||||||||||||||||||||||||||||||||||||||||||||||||||
Hungarian | benzol (benzol, benzole). (various references) | ||||||||||||||||||||||||||||||||||||||||||||||||||||
Italian | benzolo (benzol, benzole, Tokay wine), benzene (benzol, benzole, Tokay wine). (various references) | ||||||||||||||||||||||||||||||||||||||||||||||||||||
Japanese Kanji | ベンガル山猫 (gasoline, leopard cat). (various references) | ||||||||||||||||||||||||||||||||||||||||||||||||||||
Japanese Katakana | ベンゼン . (various references) | ||||||||||||||||||||||||||||||||||||||||||||||||||||
Korean | 벤 . (various references) | ||||||||||||||||||||||||||||||||||||||||||||||||||||
Manx | benseen. (various references) | ||||||||||||||||||||||||||||||||||||||||||||||||||||
Pig Latin | enzenebay benzeno (benzol). (various references) benzen. (various references) бензол (benzol, benzole, carbon oil). (various references) benzol (benzol, benzole). (various references) benceno (benzol, benzole). (various references) bensen. (various references) benzen. (various references) бензол. (various references) | ||||||||||||||||||||||||||||||||||||||||||||||||||||
Derivations | |
Words beginning with "benzene": benzenes. (additional references) | |
Words ending with "benzene": chlorobenzene, dichlorobenzene, dinitrobenzene, ethylbenzene, nitrobenzene, paradichlorobenzene. (additional references) | |
Words containing "benzene": chlorobenzenes, dichlorobenzenes, dinitrobenzenes, ethylbenzenes, nitrobenzenes, paradichlorobenzenes. (additional references) | |
| |
"Benzene" is suggested in spellcheckers for the following: Banzie, Benazzi, bencene, benden, Beneke, Benenden, benenin, benez, Bengzon, Benteen, benzenic, benzenoid, Benzie, Benzin, Benzinol, benzxene, Benzyne, Bezdna, bezen, bienvenu, Bonzanna, Genzen, Genzken, Penzini. (additional references) | |
| Source: compiled by the editor, based on several corpora (additional references). | |
| # of Phoneme Matches | Pronunciation | Word(s) rhyming with "benzene" (pronounced benzē"n or be"nzēn) |
| 3 | -z ē" n | cuisine. |
| 6 | b e" n z ē n | benzine. |
Source: compiled by the editor (additional references); see credits. | ||
Scrabble® Enable2K-Verified Anagrams | |
| Words within the letters "b-e-e-e-n-n-z" | |
-2 letters: benne. | |
-3 letters: been, bene, nene. | |
-4 letters: bee, ben, neb, nee, zee. | |
-5 letters: be, en, ne. | |
| Words containing the letters "b-e-e-e-n-n-z" | |
+1 letter: benzenes. | |
+4 letters: bedizenment. | |
+5 letters: bedizenments, benzoapyrene, benzophenone, brazennesses, ethylbenzene, nitrobenzene. | |
| Source: compiled by the editor from various references; see credits. SCRABBLE® is a registered trademark. All intellectual property rights in and to the game are owned in the U.S.A and Canada by Hasbro Inc., and throughout the rest of the world by J.W. Spear & Sons Limited of Maidenhead, Berkshire, England, a subsidiary of Mattel Inc. Mattel and Spear are not affiliated with Hasbro. | |
Hexadecimal (or equivalents, 770AD-1900s) (references)42 65 6E 7A 65 6E 65 |
| Leonardo da Vinci (1452-1519; backwards) (references)
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| American Sign Language (origins from 1620-1817 in Italy and, especially, France) (references)
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| Semaphore (1791, in France) (references)
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| Braille (1829, in France) (references)
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Morse Code (1836) (references)-... . -. --.. . -. . |
| Dancing Men (Sir Arthur Conan Doyle, 1903) (references)
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Binary Code (1918-1938, probably earlier) (references)01000010 01100101 01101110 01111010 01100101 01101110 01100101 |
HTML Code (1990) (references)B e n z e n e |
ISO 10646 (1991-1993) (references)0042 0065 006E 007A 0065 006E 0065 |
| British Sign Language (Fingerspelling, BSL; 1992, British Deaf Association Dictionary of British Sign Language) (references)
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Encryption (beginner's substitution cypher): (references)36718092718071 |
| 1. Definition 2. Synonyms 3. Crosswords 4. Usage: Commercial | 5. Quotations: Non-fiction 6. Usage Frequency 7. Expressions 8. Expressions: Internet | 9. Translations: Modern 10. Derivations 11. Rhymes 12. Anagrams | 13. Orthography 14. Bibliography |
Copyright © Philip M. Parker, INSEAD. Terms of Use.
