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Paraffin

  • Paraffin is a common name for a group of high molecular weight alkane hydrocarbons with the general formula CnH2n+2, where n is greater than about 20.
  • In the United Kingdom and South Africa the fuel known elsewhere as kerosene is called paraffin oil (or just paraffin), and the solid forms of paraffin are called paraffin wax.
  • Paraffin is also a technical name for an alkane in general, but in most cases it refers specifically to a linear, or normal alkane, while branched, or isoalkanes are also called isoparaffins. (Latin para+affinis with the meaning here of "lacking affinity", or "lacking reactivity")

Alkane products

It is mostly found as a white, odorless, tasteless, waxy solid, with a typical melting point between about 47°C and 65°C. It is insoluble in water, but soluble in ether, benzene, and certain esters. Paraffin is unaffected by most common chemical reagents, but burns readily.

Uses

Food-grade paraffin wax is used in some candies to make them look shiny. Although edible, it is nondigestible; it passes right through the body without being broken down. Non-food grade paraffin wax can contain oils and other impurities which may be toxic or harmful.

Paraffin wax is not used much to make original models for casting, as it is relatively brittle at room temperature and usually cannot be cold-carved without excessive chipping and breaking. Soft, pliable waxes such as beeswax are preferred for modelling.

See also: aliphatic hydrocarbon.



07-14-2008 23:18:10
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