Editing Petroleum ether (section)

== Properties ==
[[File:Petroleum ether.JPG|thumb|left|litre bottle]]
The very lightest, most volatile liquid hydrocarbon solvents that can be bought from laboratory chemical suppliers may also be offered under the name petroleum ether. Petroleum ether consists mainly of aliphatic hydrocarbons and is usually low in [[aromatics]]. It is commonly [[hydrodesulfurized]] and may be [[hydrogenate]]d to reduce the amount of aromatic and other [[Saturated and unsaturated compounds|unsaturated]] hydrocarbons. Petroleum ether bears normally a descriptive suffix giving the boiling range. Thus, from the leading international laboratory chemical suppliers it is possible to buy various petroleum ethers with boiling ranges such as 30–50&nbsp;°C, 40–60&nbsp;°C, 50–70&nbsp;°C, 60–80&nbsp;°C, etc. In the United States, [[chemical purity|laboratory-grade]] aliphatic hydrocarbon solvents with boiling ranges as high as 100–140&nbsp;°C may be called petroleum ether, rather than petroleum spirit.<ref name="phenix">{{citation | author=Alan Phenix | title=Generic Hydrocarbon Solvents: a Guide to Nomenclature | journal=[[Western Association for Art Conservation#Newsletter|WAAC Newsletter]] | volume=29 | issue=2 | year=2007 | url=http://cool.conservation-us.org/waac/wn/wn29/wn29-2/wn29-204.pdf}}</ref>

It is not advisable to employ a fraction with a wider boiling point range than 20&nbsp;°C, because of possible loss of the more volatile portion during its use in recrystallisation, etc., and consequent different solubilising properties of the higher boiling residue.<ref name="vogel">{{citation | author=[[Arthur Vogel (chemist)|Arthur I. Vogel]] | title=Practical Organic Chemistry | edition=5th | publisher=Longman | year=1989 | pages=397–398 | url=https://archive.org/details/TextbookOfPracticalOrganicChemistry5thEd}}</ref>

Most of the unsaturated hydrocarbons may be removed by shaking two or three times with 10% of the volume worth of concentrated [[sulfuric acid]]; vigorous shaking is then continued with successive portions of a concentrated solution of [[potassium permanganate]] in 10% sulfuric acid until the color of the permanganate remains unchanged. The solvent is then thoroughly washed with [[sodium carbonate]] solution and then with water, dried over anhydrous [[calcium chloride]], and distilled. If required perfectly dry, it can be allowed to stand over [[sodium]] wire, or [[calcium hydride]].<ref name="vogel" />