In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. Hydrocarbons from which one hydrogen atom has been removed are functional groups, called hydrocarbyls. Aromatic hydrocarbons (arenes), alkanes, alkenes, cycloalkanes and alkyne-based compounds are different types of hydrocarbons.
The majority of hydrocarbons found naturally occur in crude oil, where decomposed organic matter provides an abundance of carbon and hydrogen which, when bonded, can catenate to form seemingly limitless chains.
Hydrocarbons can be gases (e.g. methane and propane), liquids (e.g. hexane and benzene), waxes or low melting solids (e.g. paraffin wax and naphthalene) or polymers (e.g. polyethylene, polypropylene and polystyrene).
This inherent ability of hydrocarbons to bond to themselves is referred to as catenation, and allows hydrocarbon to form more complex molecules, such as cyclohexane,and in rarer cases, arenes such as benzene. This ability comes from the fact that bond character between carbon atoms is entirely non-polar,in that the distribution of electrons between the two elements is somewhat even due to the same electronegativity values of the elements (~0.30), and does not result in the formation of an electrophile.
Generally, with catenation comes the loss of the total amount of bonded hydrocarbons and an increase in the amount of energy required for bond cleavage due to strain exerted upon the molecule;in molecules such as cyclohexane, this is referred to as ring strain, and occurs due to the "destabilized" spatial electron configuration of the atom.
In simple chemistry, as per valence bond theory, the carbon atom must follow the "''4-hydrogen rule''",which states that the maximum number of atoms available to bond with carbon is equal to the number of electrons that are attracted into the outer shell of carbon.In terms of shells, carbon consists of an incomplete outer shell, which comprises 4 electrons,and thus has 4 electrons available for covalent or dative bonding.
Hydrocarbons are hydrophobic and are lipids.
Some hydrocarbons also are abundant in the solar system. Lakes of liquid methane and ethane have been found on Titan, Saturn's largest moon, confirmed by the Cassini-Huygens Mission. Hydrocarbons are also abundant in nebulae forming polycyclic aromatic hydrocarbons - PAH compounds.
!Number ofcarbon atoms | !Alkane | !Alkene | !Alkyne | !Cycloalkane | !Alkadiene |
1 | Methane| | – | – | – | – |
2 | Ethane| | Ethene (ethylene) | Acetylene>Ethyne (acetylene) | – | – |
3 | Propane| | Propene (propylene) | Methylacetylene>Propyne (methylacetylene) | Cyclopropane | Propadiene (allene) |
4 | Butane| | Butene (butylene) | Butyne | Cyclobutane | 1,3-Butadiene>Butadiene |
5 | Pentane| | Pentene | Pentyne | Cyclopentane | Piperylene>Pentadiene (piperylene) |
6 | Hexane| | Hexene | Hexyne | Cyclohexane | Hexadiene |
7 | Heptane| | Heptene | Heptyne | Cycloheptane | Heptadiene |
8 | Octane| | Octene | Octyne | Cyclooctane | Octadiene |
9 | Nonane| | Nonene | Nonyne | Cyclononane | Nonadiene |
10 | Decane| | Decene | Decyne | Cyclodecane | Decadiene |
Mixtures of volatile hydrocarbons are now used in preference to the chlorofluorocarbons as a propellant for aerosol sprays, due to chlorofluorocarbon's impact on the ozone layer.
Methane [1C] and ethane [2C] are gaseous at ambient temperatures and cannot be readily liquefied by pressure alone. Propane [3C] is however easily liquefied, and exists in 'propane bottles' mostly as a liquid. Butane [4C] is so easily liquefied that it provides a safe, volatile fuel for small pocket lighters. Pentane [5C] is a clear liquid at room temperature, commonly used in chemistry and industry as a powerful nearly odorless solvent of waxes and high molecular weight organic compounds, including greases. Hexane [6C] is also a widely used non-polar, non-aromatic solvent, as well as a significant fraction of common gasoline.
The [6C] through [10C] alkanes, alkenes and isomeric cycloalkanes are the top components of gasoline, naptha, jet fuel and specialized industrial solvent mixtures. With the progressive addition of carbon units, the simple non-ring structured hydrocarbons have higher viscosities, lubricating indices, boiling points, solidification temperatures, and deeper color. At the opposite extreme from [1C] methane lie the heavy tars that remain as the ''lowest fraction'' in a crude oil refining retort. They are collected and widely utilized as roofing compounds, pavement composition, wood preservatives (the creosote series) and as extremely high viscosity sheer-resisting liquids.
Common properties of hydrocarbons are the facts that they produce steam, carbon dioxide and heat during combustion and that oxygen is required for combustion to take place. The simplest hydrocarbon, methane, burns as follows:
:CH4 + 2 O2 → 2 H2O + CO2 + Energy
Another example of this property is propane:
:C3H8 + 5 O2 → 4 H2O + 3 CO2 + Energy
:CnH2n+2 + (3n+1)/2 O2 → (n+1) H2O + n CO2 + Energy
Burning of hydrocarbons is an example of exothermic chemical reaction.
The extraction of liquid hydrocarbon fuel from sedimentary basins is integral to modern energy development. Hydrocarbons are mined from tar sands and oil shale, and potentially extracted from sedimentary methane hydrates. These reserves require distillation and upgrading to produce synthetic crude and petroleum.
Oil reserves in sedimentary rocks are the source of hydrocarbons for the energy, transport and petrochemical industry.
Hydrocarbons are economically important because major fossil fuels such as coal, petroleum and natural gas, and its derivatives such as plastics, paraffin, waxes, solvents and oils are hydrocarbons. Hydrocarbons — along with NOx and sunlight – contribute to the formation of tropospheric ozone and greenhouse gases.
Category:Soil contamination * Category:Fossil fuels Category:Petroleum Category:Oilfield terminology
am:ሀይድሮካርቦን ar:هيدروكربون az:Karbohidrogenlər bg:Въглеводород ca:Hidrocarbur cs:Uhlovodíky cy:Hydrocarbon da:Kulbrinte de:Kohlenwasserstoffe et:Süsivesinikud el:Υδρογονάνθρακες es:Hidrocarburo eo:Hidrokarbono fa:هیدروکربن fr:Hydrocarbure ga:Hidreacarbón gl:Hidrocarburo ko:탄화수소 hi:हाइड्रोकार्बन hr:Ugljikovodici io:Hidrokarbido id:Hidrokarbon is:Kolvetni it:Idrocarburi he:פחמימן jv:Hidrokarbon ht:Idwokabi la:Carbonium hydrogenatum lv:Ogļūdeņraži lb:Kuelewaasserstoffer lt:Angliavandenilis hu:Szénhidrogének mk:Јаглеводород mr:कर्बोदक ms:Hidrokarbon mn:Нүүрсустөрөгч nl:Koolwaterstof ja:炭化水素 no:Hydrokarbon nn:Hydrokarbon oc:Idrocarbur pl:Węglowodory pt:Hidrocarboneto ro:Hidrocarbură ru:Углеводороды sq:Hidrokarburet scn:Idrucarburu si:හයිඩ්රොකාබන simple:Hydrocarbon sk:Uhľovodík sl:Ogljikovodik sr:Угљоводоник sh:Угљоводоник su:Hidrokarbon fi:Hiilivety sv:Kolväte ta:ஹைடிரோகார்பன் th:ไฮโดรคาร์บอน tr:Hidrokarbon uk:Вуглеводні ur:آبکاربن vi:Hiđrôcacbon zh-yue:烴 zh:烃This text is licensed under the Creative Commons CC-BY-SA License. This text was originally published on Wikipedia and was developed by the Wikipedia community.
After a brief spell at Setanta, during which time he produced as well as directed an exclusive documentary on Didier Drogba, Alex joined Sky Sports in September 2007 as their Champions League reporter. During his time with Sky, Alex has interviewed such stars as Eric Cantona, Gianfranco Zola, Michel Platini, Karim Benzema, Patrice Evra, Lionel Messi, Gerard Houllier, Didier Drogba and Kaka.
He is also a regular contributor to the Daily Telegraph newspaper and Icon Magazine.
Alex is the author of two books: ''The French Revolution'', a book about the influence of Gallic footballers in the UK and Claude Makelele's Autobiography "Tout Simplement".
This text is licensed under the Creative Commons CC-BY-SA License. This text was originally published on Wikipedia and was developed by the Wikipedia community.
The World News (WN) Network, has created this privacy statement in order to demonstrate our firm commitment to user privacy. The following discloses our information gathering and dissemination practices for wn.com, as well as e-mail newsletters.
We do not collect personally identifiable information about you, except when you provide it to us. For example, if you submit an inquiry to us or sign up for our newsletter, you may be asked to provide certain information such as your contact details (name, e-mail address, mailing address, etc.).
When you submit your personally identifiable information through wn.com, you are giving your consent to the collection, use and disclosure of your personal information as set forth in this Privacy Policy. If you would prefer that we not collect any personally identifiable information from you, please do not provide us with any such information. We will not sell or rent your personally identifiable information to third parties without your consent, except as otherwise disclosed in this Privacy Policy.
Except as otherwise disclosed in this Privacy Policy, we will use the information you provide us only for the purpose of responding to your inquiry or in connection with the service for which you provided such information. We may forward your contact information and inquiry to our affiliates and other divisions of our company that we feel can best address your inquiry or provide you with the requested service. We may also use the information you provide in aggregate form for internal business purposes, such as generating statistics and developing marketing plans. We may share or transfer such non-personally identifiable information with or to our affiliates, licensees, agents and partners.
We may retain other companies and individuals to perform functions on our behalf. Such third parties may be provided with access to personally identifiable information needed to perform their functions, but may not use such information for any other purpose.
In addition, we may disclose any information, including personally identifiable information, we deem necessary, in our sole discretion, to comply with any applicable law, regulation, legal proceeding or governmental request.
We do not want you to receive unwanted e-mail from us. We try to make it easy to opt-out of any service you have asked to receive. If you sign-up to our e-mail newsletters we do not sell, exchange or give your e-mail address to a third party.
E-mail addresses are collected via the wn.com web site. Users have to physically opt-in to receive the wn.com newsletter and a verification e-mail is sent. wn.com is clearly and conspicuously named at the point of
collection.If you no longer wish to receive our newsletter and promotional communications, you may opt-out of receiving them by following the instructions included in each newsletter or communication or by e-mailing us at michaelw(at)wn.com
The security of your personal information is important to us. We follow generally accepted industry standards to protect the personal information submitted to us, both during registration and once we receive it. No method of transmission over the Internet, or method of electronic storage, is 100 percent secure, however. Therefore, though we strive to use commercially acceptable means to protect your personal information, we cannot guarantee its absolute security.
If we decide to change our e-mail practices, we will post those changes to this privacy statement, the homepage, and other places we think appropriate so that you are aware of what information we collect, how we use it, and under what circumstances, if any, we disclose it.
If we make material changes to our e-mail practices, we will notify you here, by e-mail, and by means of a notice on our home page.
The advertising banners and other forms of advertising appearing on this Web site are sometimes delivered to you, on our behalf, by a third party. In the course of serving advertisements to this site, the third party may place or recognize a unique cookie on your browser. For more information on cookies, you can visit www.cookiecentral.com.
As we continue to develop our business, we might sell certain aspects of our entities or assets. In such transactions, user information, including personally identifiable information, generally is one of the transferred business assets, and by submitting your personal information on Wn.com you agree that your data may be transferred to such parties in these circumstances.