Cyclopentane

Cyclopentane
Skeletal formula
Space-filling model
Names
Preferred IUPAC name
Cyclopentane
Other names
pentamethylene
Identifiers
3D model (JSmol)
ChEBI
ChemSpider
ECHA InfoCard 100.005.470 Edit this at Wikidata
EC Number
  • 206-016-6
RTECS number
  • GY2390000
UNII
  • InChI=1S/C5H10/c1-2-4-5-3-1/h1-5H2 checkY
    Key: RGSFGYAAUTVSQA-UHFFFAOYSA-N checkY
  • InChI=1/C5H10/c1-2-4-5-3-1/h1-5H2
    Key: RGSFGYAAUTVSQA-UHFFFAOYAL
  • C1CCCC1
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 45 kPa (20 °C) [2]
Acidity (pKa) ~45
-59.18·10−6 cm3/mol
1.4065
Hazards
Occupational safety and health (OHS/OSH):
Main hazards
 Flammable[3]
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 1: Exposure would cause irritation but only minor residual injury. E.g. turpentineFlammability 3: Liquids and solids that can be ignited under almost all ambient temperature conditions. Flash point between 23 and 38 °C (73 and 100 °F). E.g. gasolineInstability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no code
1
3
0
Flash point −37.2 °C (−35.0 °F; 236.0 K)
361 °C (682 °F; 634 K)
Explosive limits 1.1%-8.7%[3]
NIOSH (US health exposure limits):
PEL (Permissible)
 none[3]
REL (Recommended)
 TWA 600 ppm (1720 mg/m3)[3]
IDLH (Immediate danger)
 N.D.[3]
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).
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Cyclopentane (also called C pentane)[4] 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.[5]

  1. ^ Record of cyclopentane in the GESTIS Substance Database of the Institute for Occupational Safety and Health, accessed on 28 February 2015.
  2. ^ "ICSC 0353 - CYCLOPENTANE".
  3. ^ a b c d e NIOSH Pocket Guide to Chemical Hazards. "#0171". National Institute for Occupational Safety and Health (NIOSH).
  4. ^ Sárkány, A.; Gaál, J.; Toth, L. (1981). "Comparative Study of C-Pentane and N-Pentane Transformations on Ni and Pt Catalysts". Studies in Surface Science and Catalysis. 7: 291–301. doi:10.1016/S0167-2991(09)60278-0.
  5. ^ Wislicenus, J.; Hentschel, W. (January 1893). "III. Der Pentamethenylalkohol und seine Derivate (Cyclopentanol and its derivatives)". Justus Liebigs Annalen der Chemie. 275 (2–3): 322–330. doi:10.1002/jlac.18932750216.