Cyclopentane

Cyclopentane
Names
	Preferred IUPAC name Cyclopentane
	Other names pentamethylene
Identifiers
CAS Number	287-92-3 ;
3D model (JSmol)	Interactive image;
ChEBI	CHEBI:23492 ;
ChemSpider	8896 ;
ECHA InfoCard	100.005.470
EC Number	206-016-6;
PubChem CID	9253;
RTECS number	GY2390000;
UNII	T86PB90RNU ;
CompTox Dashboard (EPA)	DTXSID6024886 ;
	InChI InChI=1S/C5H10/c1-2-4-5-3-1/h1-5H2 Key: RGSFGYAAUTVSQA-UHFFFAOYSA-N ; InChI=1/C5H10/c1-2-4-5-3-1/h1-5H2 Key: RGSFGYAAUTVSQA-UHFFFAOYAL;
	SMILES C1CCCC1;
Properties
Chemical formula	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)
Solubility in water	156 mg·l−1 (25 °C)
Solubility	soluble in ethanol, acetone, ether
Vapor pressure	45 kPa (20 °C)
Acidity (pKa)	~45
Magnetic susceptibility (χ)	-59.18·10−6 cm3/mol
Refractive index (nD)	1.4065
Hazards
	Occupational safety and health (OHS/OSH):
Main hazards	Flammable
NFPA 704 (fire diamond)	1 3 0
Flash point	−37.2 °C (−35.0 °F; 236.0 K)
Autoignition; temperature	361 °C (682 °F; 634 K)
Explosive limits	1.1%-8.7%
	NIOSH (US health exposure limits):
PEL (Permissible)	none
REL (Recommended)	TWA 600 ppm (1720 mg/m3)
IDLH (Immediate danger)	N.D.
Related compounds
Related compounds	cyclopropane, cyclobutane, cyclohexane
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) Infobox references

Cyclopentane (also called C pentane) 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 freezing 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 carbon rings. 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.^[4]

^ Record of cyclopentane in the GESTIS Substance Database of the Institute for Occupational Safety and Health, accessed on 28 February 2015.
^ "ICSC 0353 - CYCLOPENTANE".
^ ^a ^b ^c ^d ^e NIOSH Pocket Guide to Chemical Hazards. "#0171". National Institute for Occupational Safety and Health (NIOSH).
^ 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.