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Methane (data page)

This page provides supplementary chemical data on methane.

Last revised
Jul 6, 2026
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Wikipedia ↗

This page provides supplementary chemical data on methane.

Material Safety Data Sheet

The handling of this chemical may incur notable safety precautions.1

Structure and properties

Structure and properties
Index of refraction, nD 1.0004442
Dielectric constant, εr 1.6761 ε0 at −182 °C3
1.0008181 ε0 at −20 °C4
Bond strength ?
Bond length 0.10870 nm 5
Bond angle 109.5°
Magnetic susceptibility −17.4×10−6 cm3/mol6

Thermodynamic properties

Phase behavior
Triple point 90.67 K (−182.48 °C), 0.117 bar7
Critical point 190.6 K (−82.6 °C), 46.0 bar7
Std enthalpy change
of fusion, ΔfusHo 		1.1 kJ/mol
Std entropy change
of fusion, ΔfusSo 		12.1 J/(mol·K)
Std enthalpy change
of vaporization, ΔvapHo 		8.17 kJ/mol
Std entropy change
of vaporization, ΔvapSo 		? 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 		? kJ/mol
Standard molar entropy,
Soliquid 		? J/(mol K)
Heat capacity, cp ? J/(mol K)
Gas properties
Std enthalpy change
of formation, ΔfHogas 		−74.6 kJ/mol8
Standard molar entropy,
Sogas 		186.3 J/(mol K)8
Enthalpy of combustion ΔcHo −802 kJ/mol9
Heat capacity, cp 35.7 J/(mol K)8
van der Waals' constants10 a = 228.29 L2 kPa/mol2
b = 0.04278 L/mol

Vapor pressure of liquid

P (mm Hg) 1 10 40 100 400 760 1520 3800 7600 15200 30400 45600
T (°C) −205.9(s) −195.5(s) −187.7(s) −181.4 −168.8 −161.5 −152.3 −138.3 −124.8 −108.5 −86.3   —

Table data obtained from CRC Handbook of Chemistry and Physics 44th ed. Annotation "(s)" indicates equilibrium temperature of vapor over solid. Otherwise temperature is equilibrium of vapor over liquid. Note that these are all negative temperature values.

Methane vapor pressure vs. temperature. Uses formula log 10 ⁡ P mm Hg = 6.61184 − 389.93 266.00 + T ∘ C {\displaystyle \log _{10}P_{\text{mm Hg}}=6.61184-{\frac {389.93}{266.00+T_{^{\circ }{\text{C}}}}}} given in Lange's Handbook of Chemistry, 10th ed. Note that formula loses accuracy near Tcrit = −82.6 °C source ↗

Spectral data

Methane infrared spectrum source ↗
UV-Vis
λmax ? nm
Extinction coefficient, ε ?
IR
Major absorption bands 3019, 2917, 1534, 1306 cm−111
NMR
Proton NMR  
Carbon-13 NMR −2.3 ppm12
Other NMR data  
MS
Masses of
main fragments 		 
  This box:
  
References

References

  1. Material Safety Datasheet . Iowa State
  2. Haynes, p. 10.256
  3. Haynes, p. 6.212
  4. Haynes, p. 6.221
  5. Haynes, p. 9.45
  6. Haynes, p. 3.578
  7. Haynes, p. 6.175
  8. Haynes, p. 5.26
  9. Haynes, p. 5.67
  10. Lange's Handbook of Chemistry, 10th ed, pp. 1522–1524.
  11. Haynes, p. 9.106
  12. Haynes, p. 8.67

Cited sources