Acetylene
- Formula: C2H2
- Molecular weight: 26.0373
- IUPAC Standard InChI: InChI=1S/C2H2/c1-2/h1-2H
- IUPAC Standard InChIKey: HSFWRNGVRCDJHI-UHFFFAOYSA-N
- CAS Registry Number: 74-86-2
- 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: Ethyne; Ethine; Narcylen; C2H2; Acetylen; UN 1001; Vinylene
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Gas phase thermochemistry data
Go To: Top, 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
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔfH°gas | 226.73 | kJ/mol | Review | Chase, 1998 | Data last reviewed in March, 1961 |
| ΔfH°gas | 227.4 ± 0.8 | kJ/mol | Review | Manion, 2002 | adopted recommendation of Gurvich, Veyts, et al., 1991; DRB |
| ΔfH°gas | 226.7 ± 0.79 | kJ/mol | Ccb | Wagman, Kilpatrick, et al., 1945 | Unpublished work of E. J. Prosen; ALS |
| Quantity | Value | Units | Method | Reference | Comment |
| S°gas,1 bar | 200.93 | J/mol*K | Review | Chase, 1998 | Data last reviewed in March, 1961 |
Constant pressure heat capacity of gas
| Cp,gas (J/mol*K) | Temperature (K) | Reference | Comment |
|---|---|---|---|
| 29.35 | 100. | Gurvich, Veyts, et al., 1989 | p=1 bar.; GT |
| 35.57 | 200. | ||
| 44.04 | 298.15 | ||
| 44.17 | 300. | ||
| 50.39 | 400. | ||
| 54.75 | 500. | ||
| 58.12 | 600. | ||
| 60.97 | 700. | ||
| 63.51 | 800. | ||
| 65.83 | 900. | ||
| 67.96 | 1000. | ||
| 69.91 | 1100. | ||
| 71.69 | 1200. | ||
| 73.30 | 1300. | ||
| 74.76 | 1400. | ||
| 76.08 | 1500. | ||
| 77.27 | 1600. | ||
| 78.35 | 1700. | ||
| 79.32 | 1800. | ||
| 80.21 | 1900. | ||
| 81.01 | 2000. | ||
| 81.74 | 2100. | ||
| 82.41 | 2200. | ||
| 83.03 | 2300. | ||
| 83.60 | 2400. | ||
| 84.12 | 2500. | ||
| 84.61 | 2600. | ||
| 85.06 | 2700. | ||
| 85.49 | 2800. | ||
| 85.89 | 2900. | ||
| 86.26 | 3000. |
Gas Phase Heat Capacity (Shomate Equation)
Cp° = 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
Cp = heat capacity (J/mol*K)
H° = standard enthalpy (kJ/mol)
S° = standard entropy (J/mol*K)
t = temperature (K) / 1000.
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| Temperature (K) | 298. to 1100. | 1100. to 6000. |
|---|---|---|
| A | 40.68697 | 67.47244 |
| B | 40.73279 | 11.75110 |
| C | -16.17840 | -2.021470 |
| D | 3.669741 | 0.136195 |
| E | -0.658411 | -9.806418 |
| F | 210.7067 | 185.4550 |
| G | 235.0052 | 253.5337 |
| H | 226.7314 | 226.7314 |
| Reference | Chase, 1998 | Chase, 1998 |
| Comment | Data last reviewed in March, 1961 | Data last reviewed in March, 1961 |
References
Go To: Top, Gas phase thermochemistry data, Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Chase, 1998
Chase, M.W., Jr.,
NIST-JANAF Themochemical Tables, Fourth Edition,
J. Phys. Chem. Ref. Data, Monograph 9, 1998, 1-1951. [all data]
Manion, 2002
Manion, J.A.,
Evaluated Enthalpies of Formation of the Stable Closed Shell C1 and C2 Chlorinated Hydrocarbons,
J. Phys. Chem. Ref. Data, 2002, 31, 1, 123-172, https://doi.org/10.1063/1.1420703
. [all data]
Gurvich, Veyts, et al., 1991
Thermodynamic Properties of Individual Substances, 4th edition, Volume 2, Gurvich, L.V.; Veyts, I.V.; Alcock, C.B.;, ed(s)., Hemisphere, New York, 1991. [all data]
Wagman, Kilpatrick, et al., 1945
Wagman, D.D.; Kilpatrick, J.E.; Pitzer, K.S.; Rossini, F.D.,
Heats, equilibrium constants, and free energies of formation of the acetylene hydrocarbons through the pentynes, to 1,500° K,
J. Res. NBS, 1945, 35, 467-496. [all data]
Gurvich, Veyts, et al., 1989
Gurvich, L.V.; Veyts, I.V.; Alcock, C.B.,
Thermodynamic Properties of Individual Substances, 4th ed.; Vols. 1 and 2, Hemisphere, New York, 1989. [all data]
Notes
Go To: Top, Gas phase thermochemistry data, References
- Symbols used in this document:
Cp,gas Constant pressure heat capacity of gas S°gas,1 bar Entropy of gas at standard conditions (1 bar) ΔfH°gas Enthalpy of formation of gas at standard conditions - Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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