Pentane

C₅H₁₂Molar mass72.151 g·mol Appearance Colourless liquid OdorGasoline-like Density0.626 g/mL; 0.6262 g/mL (20 °C) Melting point−130.5 to −129.1 °C; −202.8 to −200.3 °F; 142.7 to 144.1 K Boiling point35.9 to 36.3 °C; 96.5 to 97.3 °F; 309.0 to 309.4 K

Solubility in water

40 mg/L (20 °C) log P3.255 Vapor pressure57.90 kPa (20.0 °C)

Henry's law
constant (k_H)

7.8 nmol Pa kg Acidity (pK_a) ~45 Basicity (pK_b) ~59 UV-vis (λ_max) 200 nm

Magnetic susceptibility (χ)

−63.05·10 cm/mol

Refractive index (n_D)

1.358 Viscosity0.240 mPa·s (at 20 °C) Thermochemistry

Heat capacity(C)

167.19 J K mol

Std molar
entropy(S₂₉₈)

263.47 J K mol

Std enthalpy of
formation(Δ_fH₂₉₈)

−174.1–−172.9 kJ mol

Std enthalpy of
combustion(Δ_cH₂₉₈)

−3.5095–−3.5085 MJ mol Hazards GHS labelling:

Pictograms

Signal word

Danger

Hazard statements

H225, H304, H336, H411

Precautionary statements

P210, P233, P240, P241, P242, P243, P261, P271, P273, P280, P301+P316, P303+P361+P353, P304+P340, P319, P331, P370+P378, P391, P403+P233, P403+P235, P405, P501NFPA 704 (fire diamond)

1

4

0

Flash point−49.0 °C (−56.2 °F; 224.2 K)

Autoignition
temperature

260.0 °C (500.0 °F; 533.1 K) Explosive limits1.5–7.8% Lethal dose or concentration (LD, LC):

LD₅₀ (median dose)

3 g kg (dermal, rabbit)
5 g kg (oral, mouse)

LC₅₀ (median concentration)

130,000 mg/m (mouse, 30 min)
128,200 ppm (mouse, 37 min)
325,000 mg/m (mouse, 2 hr) NIOSH (US health exposure limits):

PEL (Permissible)

TWA 1000 ppm (2950 mg/m)

REL (Recommended)

TWA 120 ppm (350 mg/m) C 610 ppm (1800 mg/m) [15-minute]

IDLH (Immediate danger)

1500 ppm Related compounds

Related alkanes

Supplementary data page Pentane (data page)

Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

verify ( ?)

Pentane is an organic compound with the formula C₅H₁₂—that is, an alkane with five carbon atoms. The term may refer to any of three structural isomers, or to a mixture of them: in the IUPAC nomenclature, however, pentane means exclusively the n-pentane isomer, in which case pentanes refers to a mixture of them; the other two are called isopentane (methylbutane) and neopentane (dimethylpropane). Cyclopentane is not an isomer of pentane because it has only 10 hydrogen atoms where pentane has 12.

Pentanes are components of some fuels and are employed as specialty solvents in the laboratory. Their properties are very similar to those of butanes and hexanes.