Propanoic acid, 2-methyl-
- Formula: C4H8O2
- Molecular weight: 88.1051
- IUPAC Standard InChIKey: KQNPFQTWMSNSAP-UHFFFAOYSA-N
- CAS Registry Number: 79-31-2
- 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: Isobutyric acid; α-Methylpropanoic acid; α-Methylpropionic acid; Dimethylacetic acid; Isobutanoic acid; Isopropylformic acid; 2-Methylpropanoic acid; 2-Methylpropionic acid; iso-C3H7COOH; Acetic acid, dimethyl-; Cenex RP b2; Propionic acid, 2-methyl-; Tenox IBP 2; Kyselina isomaselna; UN 2529; Methylpropanoic acid; Methylpropionic acid; 2-Propanecarboxylic acid; i-Butyric acid; NSC 62780
- 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 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.
Phase change 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:
BS - Robert L. Brown and Stephen E. Stein
TRC - Thermodynamics Research Center, NIST Boulder Laboratories, Chris Muzny director
AC - William E. Acree, Jr., James S. Chickos
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
Tboil | 427. ± 2. | K | AVG | N/A | Average of 40 out of 42 values; Individual data points |
Quantity | Value | Units | Method | Reference | Comment |
Tfus | 227. ± 2. | K | AVG | N/A | Average of 7 values; Individual data points |
Quantity | Value | Units | Method | Reference | Comment |
Tc | 605. | K | N/A | Ambrose and Ghiassee, 1987 | Uncertainty assigned by TRC = 1.5 K; TRC |
Tc | 609.40 | K | N/A | Brown, 1906 | Uncertainty assigned by TRC = 6. K; TRC |
Quantity | Value | Units | Method | Reference | Comment |
Pc | 37.00 | bar | N/A | Ambrose and Ghiassee, 1987 | Uncertainty assigned by TRC = 0.25 bar; TRC |
Quantity | Value | Units | Method | Reference | Comment |
ΔvapH° | 56.3 | kJ/mol | CGC | Verevkin, 2000 | Based on data from 303. to 378. K.; AC |
ΔvapH° | 55.5 ± 0.3 | kJ/mol | GS | Verevkin, 2000 | Based on data from 278. to 308. K.; AC |
ΔvapH° | 53. | kJ/mol | N/A | Majer and Svoboda, 1985 | |
ΔvapH° | 53.4 ± 3.0 | kJ/mol | V | Kruif and Oonk, 1979 | ALS |
ΔvapH° | 53. ± 4. | kJ/mol | C | Konicek, Wadsö, et al., 1970 | AC |
Enthalpy of vaporization
ΔvapH (kJ/mol) | Temperature (K) | Method | Reference | Comment |
---|---|---|---|---|
50.5 | 390. | N/A | Clifford, Ramjugernath, et al., 2004 | Based on data from 375. to 426. K.; AC |
55.8 ± 0.3 | 293. | GS | Verevkin, 2000 | Based on data from 278. to 308. K.; AC |
51.6 | 359. | EB | Ambrose and Ghiassee, 1987, 2 | Based on data from 344. to 445. K.; AC |
50.9 | 303. | A | Stephenson and Malanowski, 1987 | Based on data from 288. to 428. K.; AC |
45.4 | 443. | A | Stephenson and Malanowski, 1987 | Based on data from 428. to 562. K.; AC |
53. ± 3. | 398. | TE | Kruif and Oonk, 1979 | Based on data from 228. to 243. K.; AC |
Antoine Equation Parameters
log10(P) = A − (B / (T + C))
P = vapor pressure (bar)
T = temperature (K)
View plot Requires a JavaScript / HTML 5 canvas capable browser.
Temperature (K) | A | B | C | Reference | Comment |
---|---|---|---|---|---|
330.7 to 425. | 2.23908 | 459.215 | -220.378 | Kahlbaum, 1883 | Coefficents calculated by NIST from author's data. |
References
Go To: Top, Phase change data, Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Ambrose and Ghiassee, 1987
Ambrose, D.; Ghiassee, N.B.,
Vapor Pressures and Critical Temperatures and Critical Pressures of Some Alkanoic Acids: C1 to C10,
J. Chem. Thermodyn., 1987, 19, 505. [all data]
Brown, 1906
Brown, J.C.,
The critical temperature and value of ml/theta of some carbon compounds,
J. Chem. Soc., Trans., 1906, 89, 311. [all data]
Verevkin, 2000
Verevkin, S.P.,
Measurement and Prediction of the Monocarboxylic Acids Thermochemical Properties,
J. Chem. Eng. Data, 2000, 45, 5, 953-960, https://doi.org/10.1021/je990282m
. [all data]
Majer and Svoboda, 1985
Majer, V.; Svoboda, V.,
Enthalpies of Vaporization of Organic Compounds: A Critical Review and Data Compilation, Blackwell Scientific Publications, Oxford, 1985, 300. [all data]
Kruif and Oonk, 1979
Kruif, C.G.; Oonk, H.A.J.,
Enthalpies of vaporization and vapour pressures of seven aliphatic carboxylic acids,
J. Chem. Thermodyn., 1979, 11, 287-290. [all data]
Konicek, Wadsö, et al., 1970
Konicek, Jiri; Wadsö, Ingemar; Munch-Petersen, J.; Ohlson, Ragnar; Shimizu, Akira,
Enthalpies of Vaporization of Organic Compounds. VII. Some Carboxylic Acids.,
Acta Chem. Scand., 1970, 24, 2612-2616, https://doi.org/10.3891/acta.chem.scand.24-2612
. [all data]
Clifford, Ramjugernath, et al., 2004
Clifford, Scott L.; Ramjugernath, Deresh; Raal, J. David,
Subatmospheric Vapor Pressure Curves for Propionic Acid, Butyric Acid, Isobutyric Acid, Valeric Acid, Isovaleric Acid, Hexanoic Acid, and Heptanoic Acid,
J. Chem. Eng. Data, 2004, 49, 5, 1189-1192, https://doi.org/10.1021/je034180e
. [all data]
Ambrose and Ghiassee, 1987, 2
Ambrose, D.; Ghiassee, N.B.,
Vapour pressures and critical temperatures and critical pressures of some alkanoic acids: C1 to C10,
The Journal of Chemical Thermodynamics, 1987, 19, 5, 505-519, https://doi.org/10.1016/0021-9614(87)90147-9
. [all data]
Stephenson and Malanowski, 1987
Stephenson, Richard M.; Malanowski, Stanislaw,
Handbook of the Thermodynamics of Organic Compounds, 1987, https://doi.org/10.1007/978-94-009-3173-2
. [all data]
Kahlbaum, 1883
Kahlbaum, Georg W.A.,
Ueber die Abhängigkeit der Siedetemperatur vom Luftdruck,
Ber. Dtsch. Chem. Ges., 1883, 16, 2, 2476-2484, https://doi.org/10.1002/cber.188301602178
. [all data]
Notes
Go To: Top, Phase change data, References
- Symbols used in this document:
Pc Critical pressure Tboil Boiling point Tc Critical temperature Tfus Fusion (melting) point ΔvapH Enthalpy of vaporization ΔvapH° Enthalpy of vaporization 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.