The density of the alkanes usually increases with the number of carbon atoms but remains less than that of water. Hence, alkanes form the upper layer in an alkane–water mixture. [21] Molecular geometry [ edit ] sp 3-hybridization in methane. More volatile short-chain alkanes are also produced by and found in plant tissues. The Jeffrey pine is noted for producing exceptionally high levels of n-heptane in its resin, for which reason its distillate was designated as the zero point for one octane rating. Floral scents have also long been known to contain volatile alkane components, and n-nonane is a significant component in the scent of some roses. [38] Emission of gaseous and volatile alkanes such as ethane, pentane, and hexane by plants has also been documented at low levels, though they are not generally considered to be a major component of biogenic air pollution. [39] U prvoj reakciji, osim klorovodika, nastaje klormetan, u drugoj diklormetan, u trećoj triklormetan, a u četvrtoj tetraklormetan. Vsi alkani s kisikom popolnoma zgorijo v ogljikov dioksid in vodo: C nH 2n+2 + (1,5n+0,5)O 2 → (n+1)H 2O + nCO 2

Alkani s 35 ali več ogljikovimi atomi so sestavine bitumnov in se uporabljajo za asfaltiranje cest. Alkani z velikim številom ogljikovih atomov imajo majhno tržno vrednost, zato se s krekiranjem pretvarjajo v bolj uporabne alkane z manjšim številom ogljikovih atomov. methane CH 4 – one carbon and 4 hydrogen ethane C 2H 6 – two carbon and 6 hydrogen propane C 3H 8 – three carbon and 8 hydrogen butane C 4H 10 – four carbon and 10 hydrogen pentane C 5H 12 – five carbon and 12 hydrogen hexane C 6H 14 – six carbon and 14 hydrogen heptane C 7H 16 – seven carbons and 16 hydrogen octane C 8H 18 – eight carbons and 18 hydrogenRazvejane alkane imenujemo podobno kot nerazvejane le, da na začetku še izrazimo alkilno skupino, s katero se alkan identificira kot razvejan.

Alkani z več kot dvema atomoma ogljika lahko tvorijo obroče s splošno formulo C nH 2n in zanke – obroče, vezane na osnovno linearno ali razvejano ogljikovo verigo. Takšne alkane prištevamo k cikloalkanom. Alkane lahko torej v grobem delimo na acilkične (linearne in razvejane) alkane ter cikloalkane, ki vsebujejo obroče in zanke. Since alkanes have high ionization energies, the mass spectra show weak ion currents. The fragmentation pattern can be difficult to interpret, but in the case of branched chain alkanes, the carbon chain is preferentially cleaved at tertiary or quaternary carbons due to the relative stability of the resulting free radicals. The fragment resulting from the loss of a single methyl group ( M−15) is often absent, and other fragments are often spaced by intervals of fourteen mass units, corresponding to sequential loss of CH 2 groups. Emily Lakdawalla. "Titan: Arizona in an Icebox?". Archived from the original on 6 April 2008 . Retrieved 21 January 2004. Nerazvejane alkani imajo ime sestavljeno is dveh delov. Eden pove, koliko ogljikovih atomov je v molekuli, drug pa je končnica -an, kar nam pove, da je molekula alkan. George A. Olah, Schlosberg RH (1968). "Chemistry in Super Acids. I. Hydrogen Exchange and Polycondensation of Methane and Alkanes in FSO 3H–SbF 5 ("Magic Acid") Solution. Protonation of Alkanes and the Intermediacy of CH 5 + and Related Hydrocarbon Ions. The High Chemical Reactivity of "Paraffins" in Ionic Solution Reactions". Journal of the American Chemical Society. 90 (10): 2726–7. doi: 10.1021/ja01012a066.Na drugi atom C vezana su dva atoma broma. Zato pišemo broj 2, ali dva puta (jer su na tom atomu C dva atoma broma), povlaku te "dibrom". Butan se piše na kraju, spojeno s ostatkom naziva (bez povlake). Dakle, naziv ovog alkana prema IUPAC-u je 2,2-dibrombutan. di -#- -#- -#,#,#-tri -#,#-di -#- Funkcionalna skupina alkanov je alkilna skupina s splošno formulo C nH 2n+1–. Takšni funkcionalni skupini sta na primer metilna CH 3– in etilna skupina C 2H 5–. This section needs additional citations for verification. Please help improve this article by adding citations to reliable sourcesin this section. Unsourced material may be challenged and removed. ( January 2021) ( Learn how and when to remove this template message)

The International Union of Pure and Applied Chemistry (IUPAC) defines alkanes as "acyclic branched or unbranched hydrocarbons having the general formula C nH 2 n+2, and therefore consisting entirely of hydrogen atoms and saturated carbon atoms". However, some sources use the term to denote any saturated hydrocarbon, including those that are either monocyclic (i.e. the cycloalkanes) or polycyclic, despite their having a distinct general formula (i.e. cycloalkanes are C nH 2 n). H 3 C C l + 2 N a + C l C H 2 C H 3 ⟶ { C H 3 C H 2 C H 3 C H 3 C H 3 C H 3 C H 2 C H 2 C H 3 + 2 N a C l {\displaystyle \mathrm {H_{3}CCl+2\ Na+ClCH_{2}CH_{3}\longrightarrow {\begin{cases}CH_{3}CH_{2}CH_{3}\\CH_{3}CH_{3}\\CH_{3}CH_{2}CH_{2}CH_{3}\end{cases}}+2NaCl} } Разпространение [ редактиране | редактиране на кода ] The first four names were derived from methanol, ether, propionic acid and butyric acid. Alkanes with five or more carbon atoms are named by adding the suffix -ane to the appropriate numerical multiplier prefix [8] with elision of any terminal vowel ( -a or -o) from the basic numerical term. Hence, pentane, C 5H 12; hexane, C 6H 14; heptane, C 7H 16; octane, C 8H 18; etc. The numeral prefix is generally Greek; however, alkanes with a carbon atom count ending in nine, for example nonane, use the Latin prefix non-. Simple branched alkanes often have a common name using a prefix to distinguish them from linear alkanes, for example n-pentane, isopentane, and neopentane.

There are various, more specific d

Allaby, Michael, ed. (1988). "Alkanes (paraffins)". Illustrated Dictionary of Science, Andromeda. Windmill Books (Andromeda International). The carbon–hydrogen stretching mode gives a strong absorption between 2850 and 2960 cm −1, while the carbon–carbon stretching mode absorbs between 800 and 1300cm −1. The carbon–hydrogen bending modes depend on the nature of the group: methyl groups show bands at 1450cm −1 and 1375cm −1, while methylene groups show bands at 1465cm −1 and 1450cm −1. Carbon chains with more than four carbon atoms show a weak absorption at around 725cm −1. The word "alkali" is derived from Arabic al qalīy (or alkali), [1] meaning the calcined ashes (see calcination), referring to the original source of alkaline substances. A water-extract of burned plant ashes, called potash and composed mostly of potassium carbonate, was mildly basic. After heating this substance with calcium hydroxide ( slaked lime), a far more strongly basic substance known as caustic potash ( potassium hydroxide) was produced. Caustic potash was traditionally used in conjunction with animal fats to produce soft soaps, one of the caustic processes that rendered soaps from fats in the process of saponification, one known since antiquity. Plant potash lent the name to the element potassium, which was first derived from caustic potash, and also gave potassium its chemical symbol K (from the German name Kalium), which ultimately derived from al kali.Ima najmanji broj lokanta funkcioonalne skupine. Lokanti su brojevi na ugljikovim atomima na koje se direktno vežu supstituenti. Alkanes have a low solubility in water, so the content in the oceans is negligible; however, at high pressures and low temperatures (such as at the bottom of the oceans), methane can co-crystallize with water to form a solid methane clathrate (methane hydrate). Although this cannot be commercially exploited at the present time, the amount of combustible energy of the known methane clathrate fields exceeds the energy content of all the natural gas and oil deposits put together. Methane extracted from methane clathrate is, therefore, a candidate for future fuels.