Isobutane (data page)

This page provides supplementary chemical data on isobutane.

Material Safety Data SheetEdit

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 propertiesEdit

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

Thermodynamic propertiesEdit

Phase behavior
Triple point 113.55K (–159.6 °C), 0.019481 Pa
Critical point 407.7 K (134.6 °C), 3650 kPa
Std enthalpy change
of fusion
, ΔfusHo
4.54 kJ/mol
Std entropy change
of fusion
, ΔfusSo
39.92 J/(mol·K)
Std enthalpy change
of vaporization
, ΔvapHo
21.3 kJ/mol
Std entropy change
of vaporization
, ΔvapSo
81.46 J/(mol·K)
Solid properties
Std enthalpy change
of formation
, ΔfHosolid
? kJ/mol
Standard molar entropy,
? J/(mol K)
Heat capacity, cp ? J/(mol K)
Liquid properties
Std enthalpy change
of formation
, ΔfHoliquid
? kJ/mol
Standard molar entropy,
200.79 J/(mol K)
Heat capacity, cp 129.70 J/(mol K) –253°C to –13°C
Gas properties
Std enthalpy change
of formation
, ΔfHogas
–134.2 kJ/mol
Standard molar entropy,
249.7 J/(mol K)
Enthalpy of combustion, ΔcHo –2869 kJ/mol
Heat capacity, cp 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 liquidEdit

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:   obtained from Lange's Handbook of Chemistry, 10th ed.

Spectral dataEdit

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


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

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

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