Butane (data page)

This page provides supplementary chemical data on n-butane.

Material Safety Data Sheet

The handling of this chemical may incur notable safety precautions. It is highly recommend that you seek the Material Safety Datasheet (MSDS) for this chemical from a reliable source such as eChemPortal, and follow its directions.

Structure and properties

Structure and properties
Index of refraction, nD	1.3326 at 20 °C[1]
Dielectric constant, εr	1.7697 ε0 at 23 °C[2]
Symmetry group	C2h
Magnetic susceptibility	?
Surface tension	12.46 dyn/cm at 20 °C    P ≈ 225 kPa

Thermodynamic properties

Phase behavior
Density (liquid) 0 °C	600 kg/m³
Density (saturated vapor) 1 atm, -0.5 °C	2.6 kg/m³
Triple point	134.6 K (–138.5 °C), 0.7 Pa
Critical point	425.1 K (152.0 °C), 3796.0 kPa
Std enthalpy change of fusion, ΔfusHo	4.66 kJ/mol
Std entropy change of fusion, ΔfusSo	34.56 J/(mol·K)
Std enthalpy change of vaporization, ΔvapHo	22.44 kJ/mol
Std entropy change of vaporization, ΔvapSo	82.30 J/(mol·K)
Solid properties
Std enthalpy change of formation, ΔfHosolid	? kJ/mol
Standard molar entropy, Sosolid	? J/(mol K)
Heat capacity, cp	? J/(mol K)
Liquid properties
Std enthalpy change of formation, ΔfHoliquid	-147.6 kJ/mol
Standard molar entropy, Soliquid	229.7 J/(mol K)
Heat capacity, cp	132.42 J/(mol K) –262 °C to –3 °C
Gas properties
Std enthalpy change of formation, ΔfHogas	–124.7 kJ/mol
Standard molar entropy, Sogas	310.23 J/(mol K)
Enthalpy of combustion, ΔcHo	–2877.5 kJ/mol
Heat capacity, cp	98.49 J/(mol K) at 25 °C
n-butane van der Waals' constants[3]	a = 1466.2 L2 kPa/mol2 b = 0.1226 liter per mole

The data about butane density over a range of temperature [−50; +50] °C^[4]

Vapor pressure of liquid

P in mm Hg		1	10	40	100	400	760	1520	3800	7600	15200	30400	45600
T in °C		–101.5	–77.8	–59.1	–44.2	–16.3	–0.5	18.8	50.0	79.5	116.0	—	—

n-Butane: Table data obtained from CRC Handbook of Chemistry and Physics 44th ed.

Vapor pressure of n-butane. From formula: ${\displaystyle \scriptstyle \log _{10}P_{mmHg}=6.83029-{\frac {945.90}{240.0+T}}}$ obtained from Lange's Handbook of Chemistry, 10th ed.

Spectral data

UV-Vis
λmax	? nm
Extinction coefficient, ε	?
IR
Major absorption bands	? cm−1
NMR
Proton NMR
Carbon-13 NMR
Other NMR data
MS
Masses of main fragments