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 MSDS Search Engine, 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, ΔfusH^o	4.66 kJ/mol
Std entropy change of fusion, ΔfusS^o	34.56 J/(mol·K)
Std enthalpy change of vaporization, ΔvapH^o	22.44 kJ/mol
Std entropy change of vaporization, ΔvapS^o	82.30 J/(mol·K)
Solid properties
Std enthalpy change of formation, ΔfH^osolid	? kJ/mol
Standard molar entropy, S^osolid	? J/(mol K)
Heat capacity, cp	? J/(mol K)
Liquid properties
Std enthalpy change of formation, ΔfH^oliquid	-147.6 kJ/mol
Standard molar entropy, S^oliquid	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, ΔfH^ogas	–125.6 kJ/mol
Standard molar entropy, S^ogas	310.23 J/(mol K)
Enthalpy of combustion, ΔcH^o	–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 L^2 kPa/mol^2 b = 0.1226 liter per mole

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: $\scriptstyle \log_{10} P_{mmHg} = 6.83029 - \frac {945.90} {240.0+T}$ 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

References

1. CRC Handbook of Chemistry and Physics 85th ed, pp 202
2. CRC Handbook of Chemistry and Physics 85th ed, pp 1148
3. Lange's Handbook of Chemistry 10th ed, pp 1522-1524

• "Multifunctional Green Alternative: Propane and Butane (properties)". Seminck. Retrieved 1 May 2007.

Except where noted otherwise, data relate to standard ambient temperature and pressure.

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