2-Butyne
- Formula: C4H6
- Molecular weight: 54.0904
- IUPAC Standard InChI: InChI=1S/C4H6/c1-3-4-2/h1-2H3
- IUPAC Standard InChIKey: XNMQEEKYCVKGBD-UHFFFAOYSA-N
- CAS Registry Number: 503-17-3
- 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: But-2-yne; Dimethylacetylene; CH3C≡CCH3; Crotonylene; UN 1144
- Permanent link for this species. Use this link for bookmarking this species for future reference.
- Information on this page:
- Other data available:
- Data at other public NIST sites:
- Options:
Data at NIST subscription sites:
- NIST / TRC Web Thermo Tables, "lite" edition (thermophysical and thermochemical data)
- NIST / TRC Web Thermo Tables, professional edition (thermophysical and thermochemical data)
NIST subscription sites provide data under the NIST Standard Reference Data Program, but require an annual fee to access. The purpose of the fee is to recover costs associated with the development of data collections included in such sites. Your institution may already be a subscriber. Follow the links above to find out more about the data in these sites and their terms of usage.
Gas phase thermochemistry data
Go To: Top, Condensed phase 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 compiled as indicated in comments:
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 | 34.68 ± 0.24 | kcal/mol | Cm | Prosen, Maron, et al., 1951 | ALS |
| ΔfH°gas | 35.37 ± 0.35 | kcal/mol | Ccb | Wagman, Kilpatrick, et al., 1945 | Unpublished work of E. J. Prosen; ALS |
| Quantity | Value | Units | Method | Reference | Comment |
| ΔcH°gas | -615.84 ± 0.23 | kcal/mol | Cm | Prosen, Maron, et al., 1951 | Corresponding ΔfHºgas = 34.69 kcal/mol (simple calculation by NIST; no Washburn corrections); ALS |
Constant pressure heat capacity of gas
| Cp,gas (cal/mol*K) | Temperature (K) | Reference | Comment |
|---|---|---|---|
| 9.364 | 50. | Thermodynamics Research Center, 1997 | p=1 bar. Selected values are in close agreement with other statistically calculated values [ Wagman D.D., 1945].; GT |
| 11.58 | 100. | ||
| 13.55 | 150. | ||
| 15.19 | 200. | ||
| 17.71 | 273.15 | ||
| 18.65 | 298.15 | ||
| 18.72 | 300. | ||
| 22.64 | 400. | ||
| 26.381 | 500. | ||
| 29.708 | 600. | ||
| 32.622 | 700. | ||
| 35.167 | 800. | ||
| 37.392 | 900. | ||
| 39.328 | 1000. | ||
| 41.011 | 1100. | ||
| 42.474 | 1200. | ||
| 43.74 | 1300. | ||
| 44.84 | 1400. | ||
| 45.82 | 1500. |
Constant pressure heat capacity of gas
| Cp,gas (cal/mol*K) | Temperature (K) | Reference | Comment |
|---|---|---|---|
| 20.21 | 336.07 | Kistiakowsky G.B., 1940 | GT |
| 21.43 | 369.46 |
Condensed phase thermochemistry data
Go To: Top, Gas phase 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 compiled by: Eugene S. Domalski and Elizabeth D. Hearing
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| S°liquid | 46.630 | cal/mol*K | N/A | Yost, Osborne, et al., 1941 | Extrapolated from 291.0 K. Anomalous heat capacity between 145 and 160 K. S obtained from total energy divided by average temperature. |
Constant pressure heat capacity of liquid
| Cp,liquid (cal/mol*K) | Temperature (K) | Reference | Comment |
|---|---|---|---|
| 29.670 | 290. | Yost, Osborne, et al., 1941 | T = 15 to 290 K. |
References
Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Prosen, Maron, et al., 1951
Prosen, E.J.; Maron, F.W.; Rossini, F.D.,
Heats of combustion, formation, and insomerization of ten C4 hydrocarbons,
J. Res. NBS, 1951, 46, 106-112. [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]
Thermodynamics Research Center, 1997
Thermodynamics Research Center,
Selected Values of Properties of Chemical Compounds., Thermodynamics Research Center, Texas A&M University, College Station, Texas, 1997. [all data]
Wagman D.D., 1945
Wagman D.D.,
Heats, equilibrium constants, and free energies of formation of the acetylene hydrocarbons through the pentynes to 1500 K,
J. Res. Nat. Bur. Stand., 1945, 35, 467-496. [all data]
Kistiakowsky G.B., 1940
Kistiakowsky G.B.,
Gaseous heat capacities. III,
J. Chem. Phys., 1940, 8, 618-622. [all data]
Yost, Osborne, et al., 1941
Yost, D.M.; Osborne, D.W.; Garner, C.S.,
The heat capacity, entropy, and heats of transition, fusion, and vaporization of dimethylacetylene. Free rotation in the dimethylacetylene molecule,
J. Am. Chem. Soc., 1941, 63, 3492-3496. [all data]
Notes
Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, References
- Symbols used in this document:
Cp,gas Constant pressure heat capacity of gas Cp,liquid Constant pressure heat capacity of liquid S°liquid Entropy of liquid at standard conditions ΔcH°gas Enthalpy of combustion of gas at standard conditions ΔfH°gas Enthalpy of formation of gas at standard conditions - Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
- The National Institute of Standards and Technology (NIST) uses its best efforts to deliver a high quality copy of the Database and to verify that the data contained therein have been selected on the basis of sound scientific judgment. However, NIST makes no warranties to that effect, and NIST shall not be liable for any damage that may result from errors or omissions in the Database.
- Customer support for NIST Standard Reference Data products.