Isobutane (data page)

This page provides supplementary chemical data on isobutane.

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 SIRI, and follow its directions.

Structure and properties

Structure and properties
Index of refraction, n_D	?
Abbe number	?
Dielectric constant, ε_r	? ε₀ at ? °C
Bond strength	?
Bond length	?
Bond angle	?
Magnetic susceptibility	?
Surface tension	10.3 dyn/cm at 20°C P 300 kPa

Thermodynamic properties

Phase behavior
Triple point	113.55K (–159.8 °C), 0.019483 Pa
Critical point	408.7 K (134.4 °C), 3655 kPa
Std enthalpy change of fusion, Δ_fusH^o	4.59 kJ/mol
Std entropy change of fusion, Δ_fusS^o	39.92 J/(mol·K)
Std enthalpy change of vaporization, Δ_vapH^o	21.3 kJ/mol
Std entropy change of vaporization, Δ_vapS^o	81.46 J/(mol·K)
Solid properties
Std enthalpy change of formation, Δ_fH^o_solid	? kJ/mol
Standard molar entropy, S^o_solid	? J/(mol K)
Heat capacity, c_p	? J/(mol K)
Liquid properties
Std enthalpy change of formation, Δ_fH^o_liquid	? kJ/mol
Standard molar entropy, S^o_liquid	200.79 J/(mol K)
Heat capacity, c_p	129.70 J/(mol K) –253°C to –13°C
Gas properties
Std enthalpy change of formation, Δ_fH^o_gas	–134.2 kJ/mol
Standard molar entropy, S^o_gas	249.7 J/(mol K)
Enthalpy of combustion, Δ_cH^o	–2869 kJ/mol
Heat capacity, c_p	95.21 J/(mol K) at 20°C
van der Waals' constants^[1]	a = 1304.1 L² kPa/mol² b = 0.1142 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		–109.2	–86.4	–68.4	–54.1	–27.1	–11.7	7.5	39.0	68.8	99.5	—	—

Table data obtained from CRC Handbook of Chemistry and Physics 44th ed.

**Vapor pressure of *iso*-butane**. From formula: $\scriptstyle \log _{10}P_{mmHg}=6.74808-{\frac {882.80}{240.0+T}}$ obtained from *Lange's Handbook of Chemistry*, 10th ed.

Spectral data

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

This box:

Except where noted otherwise, data relate to Standard temperature and pressure.
Reliability of data general note.

References

^ Lange's Handbook of Chemistry 10th ed, pp 1522-1524

[lange1522-1] Lange's Handbook of Chemistry 10th ed, pp 1522-1524

[1]