Cyclopentane
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Names | |||
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IUPAC name
Cyclopentane
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Other names
pentamethylene
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Identifiers | |||
287-92-3 ![]() |
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ChEBI | CHEBI:23492 ![]() |
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ChemSpider | 8896 ![]() |
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EC Number | 206-016-6 | ||
Jmol 3D model | Interactive image | ||
PubChem | 9253 | ||
RTECS number | GY2390000 | ||
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Properties | |||
C5H10 | |||
Molar mass | 70.1 g/mol | ||
Appearance | clear, colorless liquid | ||
Odor | mild, sweet | ||
Density | 0.751 g/cm3 | ||
Melting point | −93.9 °C (−137.0 °F; 179.2 K) | ||
Boiling point | 49.2 °C (120.6 °F; 322.3 K) | ||
156 mg·l−1 (25 °C)[1] | |||
Solubility | soluble in ethanol, acetone, ether | ||
Vapor pressure | 400 mmHg (31 °C)[2] | ||
Acidity (pKa) | ~45 | ||
Refractive index (nD)
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1.4065 | ||
Vapor pressure | {{{value}}} | ||
Related compounds | |||
Related compounds
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cyclopropane, cyclobutane, cyclohexane | ||
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references | |||
Cyclopentane is a highly flammable alicyclic hydrocarbon with chemical formula C5H10 and CAS number 287-92-3, consisting of a ring of five carbon atoms each bonded with two hydrogen atoms above and below the plane. It occurs as a colorless liquid with a petrol-like odor. Its melting point is −94 °C and its boiling point is 49 °C. Cyclopentane is in the class of cycloalkanes, being alkanes that have one or more rings of carbon atoms.
It is formed by cracking cyclohexane in the presence of alumina at a high temperature and pressure.
It was first prepared in 1893 by the German chemist Johannes Wislicenus.[3]
Industrial usage
Cyclopentane is used in the manufacture of synthetic resins and rubber adhesives and also as a blowing agent in the manufacture of polyurethane insulating foam, as found in many domestic appliances such as refrigerators and freezers, replacing environmentally damaging alternatives such as CFC-11 and HCFC-141b[4]
Better technologies, such as computer hard drives and outerspace equipment employ multiply alkylated cyclopentane (MAC) lubricants because of their extremely low volatility.[5]
The United States produces more than half a million kilograms of this chemical per year.
Formulation of cycloalkanes
Cycloalkanes can be formulated via a process known as catalytic reforming.
For example, 2-methylbutane can be reformed into cyclopentane, by use of a platinum catalyst. This is particularly well known in automobiles, as branched alkanes will burn much more readily.
References
- ↑ Record of cyclopentane in the GESTIS Substance Database of the IFA, accessed on 28 February 2015
- ↑ Cite error: Invalid
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- ↑ J. Wislicenus and W. Hentschel (1893) "Der Pentamethenylalkohol und seine Derivate" (Cyclopentanol and its derivatives), Annalen der Chemie, 275 : 322-330; see especially pages 327-330. Wislicenus prepared cyclopentane from cyclopentanone ("Ketopentamethen"), which is prepared by heating calcium adipate.
- ↑ Greenpeace - Appliance Insulation
- ↑ Pennzane - lubrication technology