Methane

• Formula: CH₄
• Molecular weight: 16.0425
• IUPAC Standard InChI: InChI=1S/CH4/h1H4 Copy

  
• IUPAC Standard InChIKey: VNWKTOKETHGBQD-UHFFFAOYSA-N Copy
• CAS Registry Number: 74-82-8
• Chemical structure:
  This structure is also available as a 2d Mol file or as a computed 3d SD file
  The 3d structure may be viewed using Java or Javascript.
• Other names: Marsh gas; Methyl hydride; CH4; Fire Damp; R 50; Biogas; R 50 (refrigerant)
• Permanent link for this species. Use this link for bookmarking this species for future reference.
• Information on this page:
  • Gas phase thermochemistry data
  • Reaction thermochemistry data (reactions 1 to 50)
  • Gas phase ion energetics data
  • References
  • Notes
• Other data available:
  • Phase change data
  • Reaction thermochemistry data: reactions 51 to 100, reactions 101 to 112
  • Henry's Law data
  • Ion clustering data
  • IR Spectrum
  • Mass spectrum (electron ionization)
  • Vibrational and/or electronic energy levels
  • Fluid Properties
• Data at other public NIST sites:
  • Microwave spectra (on physics lab web site)
  • Electron-Impact Ionization Cross Sections (on physics web site)
  • Gas Phase Kinetics Database
• Options:
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Gas phase thermochemistry data

Go To: Top, Reaction thermochemistry data, Gas phase ion energetics data, References, Notes

Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

Data compiled as indicated in comments:
DRB - Donald R. Burgess, Jr.
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
GT - Glushko Thermocenter, Russian Academy of Sciences, Moscow

Constant pressure heat capacity of gas

Constant pressure heat capacity of gas

Gas Phase Heat Capacity (Shomate Equation)

C_p° = A + B*t + C*t² + D*t³ + E/t²
H° − H°_298.15= A*t + B*t²/2 + C*t³/3 + D*t⁴/4 − E/t + F − H
S° = A*ln(t) + B*t + C*t²/2 + D*t³/3 − E/(2*t²) + G
    C_p = heat capacity (J/mol*K)
    H° = standard enthalpy (kJ/mol)
    S° = standard entropy (J/mol*K)
    t = temperature (K) / 1000.

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Reaction thermochemistry data

Go To: Top, Gas phase thermochemistry data, Gas phase ion energetics data, References, Notes

Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

Data compiled as indicated in comments:
B - John E. Bartmess
M - Michael M. Meot-Ner (Mautner) and Sharon G. Lias
MS - José A. Martinho Simões
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein

Note: Please consider using the reaction search for this species. This page allows searching of all reactions involving this species. A general reaction search form is also available. Future versions of this site may rely on reaction search pages in place of the enumerated reaction displays seen below.

Reactions 1 to 50

CH₃^- +  =

By formula: CH₃^- + H⁺ = CH₄

(CH₅⁺ • ) +  = (CH₅⁺ • 2)

By formula: (CH₅⁺ • CH₄) + CH₄ = (CH₅⁺ • 2CH₄)

CH₅⁺ +  = (CH₅⁺ • )

By formula: CH₅⁺ + CH₄ = (CH₅⁺ • CH₄)

C₂H₅⁺ +  = (C₂H₅⁺ • )

By formula: C₂H₅⁺ + CH₄ = (C₂H₅⁺ • CH₄)

( • 2) +  = ( • 3)

By formula: (Co⁺ • 2CH₄) + CH₄ = (Co⁺ • 3CH₄)

Enthalpy of reaction

Free energy of reaction

 +  = ( • )

By formula: Co⁺ + CH₄ = (Co⁺ • CH₄)

Enthalpy of reaction

( • ) +  = ( •  • )

By formula: (Co⁺ • CH₄) + H₂ = (Co⁺ • H₂ • CH₄)

Enthalpy of reaction

( • ) +  = ( •  • )

By formula: (Co⁺ • H₂) + CH₄ = (Co⁺ • CH₄ • H₂)

Enthalpy of reaction

 (g) = C₅MnO₅ (g) +  (g)

By formula: C₆H₃MnO₅ (g) = C₅MnO₅ (g) + CH₄ (g)

( • ) +  = ( • 2)

By formula: (Co⁺ • CH₄) + CH₄ = (Co⁺ • 2CH₄)

Enthalpy of reaction

(CH₅⁺ • 2) +  = (CH₅⁺ • 3)

By formula: (CH₅⁺ • 2CH₄) + CH₄ = (CH₅⁺ • 3CH₄)

(CH₅⁺ • 3) +  = (CH₅⁺ • 4)

By formula: (CH₅⁺ • 3CH₄) + CH₄ = (CH₅⁺ • 4CH₄)

 (g) + CH₃BrMg (solution) =  (solution) + Br₂Mg (solution)

By formula: HBr (g) + CH₃BrMg (solution) = CH₄ (solution) + Br₂Mg (solution)

( • ) +  = ( •  • )

By formula: (Co⁺ • CH₄) + C₂H₆ = (Co⁺ • C₂H₆ • CH₄)

Enthalpy of reaction

C₆₃H₉₁CoN₁₃O₁₄P (solution) =  (solution) +  (solution)

By formula: C₆₃H₉₁CoN₁₃O₁₄P (solution) = C₆₃H₈₈CoN₁₄O₁₄P (solution) + CH₄ (solution)

C₃H₇⁺ +  = (C₃H₇⁺ • )

By formula: C₃H₇⁺ + CH₄ = (C₃H₇⁺ • CH₄)

 +  =  + 

By formula: HI + CH₃I = CH₄ + I₂

(C₂H₅⁺ • 9) +  = (C₂H₅⁺ • 10)

By formula: (C₂H₅⁺ • 9CH₄) + CH₄ = (C₂H₅⁺ • 10CH₄)

(C₃H₇⁺ • 7) +  = (C₃H₇⁺ • 8)

By formula: (C₃H₇⁺ • 7CH₄) + CH₄ = (C₃H₇⁺ • 8CH₄)

(C₄H₉⁺ • 8) +  = (C₄H₉⁺ • 9)

By formula: (C₄H₉⁺ • 8CH₄) + CH₄ = (C₄H₉⁺ • 9CH₄)

(CH₅⁺ • 8) +  = (CH₅⁺ • 9)

By formula: (CH₅⁺ • 8CH₄) + CH₄ = (CH₅⁺ • 9CH₄)

( • ) +  = ( •  • )

By formula: (Co⁺ • H₂O) + CH₄ = (Co⁺ • CH₄ • H₂O)

Enthalpy of reaction

( • ) +  = ( • 2)

By formula: (H₃O⁺ • CH₄) + CH₄ = (H₃O⁺ • 2CH₄)

( • ) +  = ( •  • )

By formula: (Co⁺ • C₂H₆) + CH₄ = (Co⁺ • CH₄ • C₂H₆)

Enthalpy of reaction

 +  = ( • )

By formula: H₄N⁺ + CH₄ = (H₄N⁺ • CH₄)

 (g) +  (cr) =  (g) +  (cr)

By formula: HBr (g) + CH₃Li (cr) = CH₄ (g) + BrLi (cr)

2 +  =  + 2

By formula: 2H₂ + CH₂Cl₂ = CH₄ + 2HCl

 (l) + ( • 100) (solution) = 2 (g) + ( • 100) (solution)

By formula: C₂H₆Zn (l) + (H₂O₄S • 100H₂O) (solution) = 2CH₄ (g) + (O₄SZn • 100H₂O) (solution)

(CH₅⁺ • 4) +  = (CH₅⁺ • 5)

By formula: (CH₅⁺ • 4CH₄) + CH₄ = (CH₅⁺ • 5CH₄)

(CH₅⁺ • 5) +  = (CH₅⁺ • 6)

By formula: (CH₅⁺ • 5CH₄) + CH₄ = (CH₅⁺ • 6CH₄)

(CH₅⁺ • 6) +  = (CH₅⁺ • 7)

By formula: (CH₅⁺ • 6CH₄) + CH₄ = (CH₅⁺ • 7CH₄)

(CH₅⁺ • 7) +  = (CH₅⁺ • 8)

By formula: (CH₅⁺ • 7CH₄) + CH₄ = (CH₅⁺ • 8CH₄)

(C₂H₅⁺ • 2) +  = (C₂H₅⁺ • 3)

By formula: (C₂H₅⁺ • 2CH₄) + CH₄ = (C₂H₅⁺ • 3CH₄)

(C₂H₅⁺ • 3) +  = (C₂H₅⁺ • 4)

By formula: (C₂H₅⁺ • 3CH₄) + CH₄ = (C₂H₅⁺ • 4CH₄)

(C₂H₅⁺ • 4) +  = (C₂H₅⁺ • 5)

By formula: (C₂H₅⁺ • 4CH₄) + CH₄ = (C₂H₅⁺ • 5CH₄)

(C₂H₅⁺ • 5) +  = (C₂H₅⁺ • 6)

By formula: (C₂H₅⁺ • 5CH₄) + CH₄ = (C₂H₅⁺ • 6CH₄)

(C₂H₅⁺ • 6) +  = (C₂H₅⁺ • 7)

By formula: (C₂H₅⁺ • 6CH₄) + CH₄ = (C₂H₅⁺ • 7CH₄)

(C₂H₅⁺ • 7) +  = (C₂H₅⁺ • 8)

By formula: (C₂H₅⁺ • 7CH₄) + CH₄ = (C₂H₅⁺ • 8CH₄)

(C₂H₅⁺ • 8) +  = (C₂H₅⁺ • 9)

By formula: (C₂H₅⁺ • 8CH₄) + CH₄ = (C₂H₅⁺ • 9CH₄)

(C₃H₇⁺ • 2) +  = (C₃H₇⁺ • 3)

By formula: (C₃H₇⁺ • 2CH₄) + CH₄ = (C₃H₇⁺ • 3CH₄)

(C₃H₇⁺ • 3) +  = (C₃H₇⁺ • 4)

By formula: (C₃H₇⁺ • 3CH₄) + CH₄ = (C₃H₇⁺ • 4CH₄)

(C₃H₇⁺ • 4) +  = (C₃H₇⁺ • 5)

By formula: (C₃H₇⁺ • 4CH₄) + CH₄ = (C₃H₇⁺ • 5CH₄)

(C₃H₇⁺ • 5) +  = (C₃H₇⁺ • 6)

By formula: (C₃H₇⁺ • 5CH₄) + CH₄ = (C₃H₇⁺ • 6CH₄)

(C₃H₇⁺ • 6) +  = (C₃H₇⁺ • 7)

By formula: (C₃H₇⁺ • 6CH₄) + CH₄ = (C₃H₇⁺ • 7CH₄)

(C₄H₉⁺ • 2) +  = (C₄H₉⁺ • 3)

By formula: (C₄H₉⁺ • 2CH₄) + CH₄ = (C₄H₉⁺ • 3CH₄)

(C₄H₉⁺ • 3) +  = (C₄H₉⁺ • 4)

By formula: (C₄H₉⁺ • 3CH₄) + CH₄ = (C₄H₉⁺ • 4CH₄)

(C₄H₉⁺ • 4) +  = (C₄H₉⁺ • 5)

By formula: (C₄H₉⁺ • 4CH₄) + CH₄ = (C₄H₉⁺ • 5CH₄)

(C₄H₉⁺ • 5) +  = (C₄H₉⁺ • 6)

By formula: (C₄H₉⁺ • 5CH₄) + CH₄ = (C₄H₉⁺ • 6CH₄)

(C₄H₉⁺ • 6) +  = (C₄H₉⁺ • 7)

By formula: (C₄H₉⁺ • 6CH₄) + CH₄ = (C₄H₉⁺ • 7CH₄)

(C₄H₉⁺ • 7) +  = (C₄H₉⁺ • 8)

By formula: (C₄H₉⁺ • 7CH₄) + CH₄ = (C₄H₉⁺ • 8CH₄)

Gas phase ion energetics data

Go To: Top, Gas phase thermochemistry data, Reaction thermochemistry data, References, Notes

Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

Data evaluated as indicated in comments:
HL - Edward P. Hunter and Sharon G. Lias
L - Sharon G. Lias

Data compiled as indicated in comments:
B - John E. Bartmess
LBLHLM - Sharon G. Lias, John E. Bartmess, Joel F. Liebman, John L. Holmes, Rhoda D. Levin, and W. Gary Mallard
LLK - Sharon G. Lias, Rhoda D. Levin, and Sherif A. Kafafi
RDSH - Henry M. Rosenstock, Keith Draxl, Bruce W. Steiner, and John T. Herron

View reactions leading to CH₄⁺ (ion structure unspecified)

Ionization energy determinations

Appearance energy determinations

De-protonation reactions

CH₃^- +  =

By formula: CH₃^- + H⁺ = CH₄

References

Go To: Top, Gas phase thermochemistry data, Reaction thermochemistry data, Gas phase ion energetics data, Notes

Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

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Bennet, S.L.; Field, F.H., Reversible Reactions of Gaseous Ions. VI. The NH3 - CH4, H2S - CH4 and CF4 - CH4 Systems at Low Temperatures, J. Am. Chem. Soc., 1972, 94, 18, 6305, https://doi.org/10.1021/ja00773a009 . [all data]

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Notes

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• Symbols used in this document:
  

  AE	Appearance energy
  Cp,gas	Constant pressure heat capacity of gas
  IE (evaluated)	Recommended ionization energy
  S°gas	Entropy of gas at standard conditions
  S°gas,1 bar	Entropy of gas at standard conditions (1 bar)
  T	Temperature
  ΔcH°gas	Enthalpy of combustion of gas at standard conditions
  ΔfH°gas	Enthalpy of formation of gas at standard conditions
  ΔrG°	Free energy of reaction at standard conditions
  ΔrH°	Enthalpy of reaction at standard conditions
  ΔrS°	Entropy of reaction at standard conditions

• Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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