Editing Paraffin wax (section)

== Properties ==
Paraffin [[wax]] is mostly found as a white, odorless, flavourless, waxy solid, with a typical melting point between about {{convert|46|and|68|°C|°F}},<ref>{{cite book|last=Nasser|first=William E|editor=McKetta, John J|title=Encyclopedia of Chemical Processing and Design|volume=67|year=1999|publisher=Marcel Dekker|location=New York|isbn=978-0-8247-2618-8|page=17|chapter=Waxes, Natural and Synthetic}} This can vary widely, even outside the quoted range, according to such factors as oil content and crystalline structure.</ref> and a density of around 900&nbsp;kg/m<sup>3</sup>.<ref name=kayelabymech>{{cite web
| last =Kaye
| first =George William Clarkson
| author2 =Laby, Thomas Howell
| author-link2 =T. H. Laby
| title =Mechanical properties of materials
| work =Kaye and Laby Tables of Physical and Chemical Constants
| publisher =[[National Physical Laboratory, UK|National Physical Laboratory]]
| url =http://www.kayelaby.npl.co.uk/general_physics/2_2/2_2_1.html
| access-date =25 October 2013
| archive-url =https://web.archive.org/web/20080311173419/http://www.kayelaby.npl.co.uk/general_physics/2_2/2_2_1.html
| archive-date =11 March 2008
| url-status =dead
}}</ref> It is insoluble in water, but soluble in [[diethyl ether|ether]], [[benzene]], and certain [[ester]]s. Paraffin is unaffected by most common chemical [[reagent]]s but [[combustion|burns]] readily.<ref>{{cite book|last1=Seager|first1=Spencer L.|last2=Slabaugh|first2=Michael|title=Chemistry for Today: General, Organic, and Biochemistry|publisher=Cengage|location=Belmont, California|isbn=978-0-538-73332-8|page=364|chapter=Alkane reactions|date=19 January 2010}}</ref> Its heat of combustion is 42 MJ/kg.<ref>{{Cite journal|last=Wiener|first=Harry|date=January 1947|title=Structural Determination of Paraffin Boiling Points|url=https://pubs.acs.org/doi/pdf/10.1021/ja01193a005|journal=Journal of the American Chemical Society|volume=69|issue=1|pages=17–20|doi=10.1021/ja01193a005|pmid=20291038|issn=0002-7863}}</ref>
: [[Image:Hentriacontane.svg|270px|thumb|right|The hydrocarbon [[Hentriacontane|C<sub>31</sub>H<sub>64</sub>]] is a typical component of paraffin wax.]]

Paraffin wax is an excellent [[electrical insulator]], with a [[resistivity]] of between 10<sup>13</sup> and 10<sup>17</sup> [[Resistivity|ohm-metre]].<ref name =kayelabyelec>{{cite web
| title =Electrical insulating materials
| work =Kaye and Laby Tables of Physical and Chemical Constants
| publisher =National Physical Laboratory
| year =1995
| url =http://www.kayelaby.npl.co.uk/general_physics/2_6/2_6_3.html
| access-date =25 October 2013
| archive-url =https://web.archive.org/web/20070927004133/http://www.kayelaby.npl.co.uk/general_physics/2_6/2_6_3.html
| archive-date =27 September 2007
| url-status =dead
}}</ref> This is better than nearly all other materials except some [[plastics]] (notably [[polytetrafluoroethylene|PTFE]]). It is an effective [[neutron moderator]] and was used in [[James Chadwick]]'s 1932 experiments to identify the neutron.<ref>{{cite web
| title =Attenuation of fast neutrons: neutron moderation and diffusion
| work =Kaye and Laby Tables of Physical and Chemical Constants
| publisher =National Physical Laboratory
| url =http://www.kayelaby.npl.co.uk/atomic_and_nuclear_physics/4_7/4_7_3.html
| access-date =25 October 2013
| archive-url =https://web.archive.org/web/20070929125508/http://www.kayelaby.npl.co.uk/atomic_and_nuclear_physics/4_7/4_7_3.html
| archive-date =29 September 2007
| url-status =dead
}}</ref><ref>{{cite book
| last =Rhodes
| first =Richard
| author-link =Richard Rhodes
| title =The Making of the Atomic Bomb
| publisher =Simon and Schuster
| year =1981
| location =New York
| page = [https://archive.org/details/makingofatomicbo00rhod/page/163 163]
| url =https://archive.org/details/makingofatomicbo00rhod
| url-access =registration
| isbn =978-0-671-44133-3}}</ref>

Paraffin wax is an excellent material for [[Phase change material|storing heat]], with a [[specific heat capacity]] of 2.14–2.9&nbsp;J⋅g<sup>−1</sup>⋅K<sup>−1</sup> ([[joules]] per [[gram]] per [[kelvin]]) and a [[Enthalpy of fusion|heat of fusion]] of 200–220&nbsp;J⋅g<sup>−1</sup>.<ref>{{cite encyclopedia| title =Specific Heat Capacity| encyclopedia =Diracdelta.co.uk Science and Engineering Encyclopedia| publisher =Dirac Delta Consultants Ltd, Warwick, England| url =http://www.diracdelta.co.uk/science/source/s/p/specific%20heat%20capacity/source.html| url-status =dead| access-date=25 October 2013| archive-url =https://web.archive.org/web/20070804192935/http://www.diracdelta.co.uk/science/source/s/p/specific%20heat%20capacity/source.html| archive-date =4 August 2007| df =dmy-all}}</ref> Paraffin wax phase-change cooling coupled with retractable radiators was used to cool the electronics of the [[Lunar Roving Vehicle]] during the crewed missions to the Moon in the early 1970s.<ref>{{cite journal |title=Space Station thermal storage/refrigeration system research and development |last1=Dean |first1=W. G. |last2=Karu |first2=Z. S. |date=February 1993 |journal=Final Report Lockheed Missiles and Space Co.}}</ref> Wax expands considerably when it melts and so is used in [[wax thermostatic element|wax element]] [[thermostat]]s for industrial, domestic and, particularly, automobile purposes.<ref>[http://www.freepatentsonline.com/4948043.html Wax-pellet thermostat] United States Patent 4948043</ref><ref name="rogerboden">{{cite web|url=http://hermes.material.uu.se/~klas/Paraffin_lab_eng.pdf|title=Paraffin Microactuator|last=Bodén|first=Roger|work=Materials Science Sensors and Actuators|publisher=University of Uppsala|archive-url=https://web.archive.org/web/20120208100013/http://hermes.material.uu.se/~klas/Paraffin_lab_eng.pdf|archive-date=8 February 2012|url-status=dead|access-date=25 October 2013}}</ref>

If pure paraffin wax melted to the approximate flash point in a half open glass vessel which is then suddenly cooled down, then its vapors may autoignite as result of reaching [[Boiling liquid expanding vapor explosion|boiling liquid pressure]].<ref>{{Cite web |last=Husting |first=Chad |date=2019-08-18 |title=Paraffin Wax – an Exothermic Reaction: Caution |url=https://www.chemedx.org/blog/paraffin-wax-exothermic-reaction-caution |access-date=2023-04-18 |website=Chemical Education Xchange |language=en}}</ref>