o-Xylene
- Formula: C8H10
- Molecular weight: 106.1650
- IUPAC Standard InChIKey: CTQNGGLPUBDAKN-UHFFFAOYSA-N
- CAS Registry Number: 95-47-6
- 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. - Isotopologues:
- Other names: Benzene, 1,2-dimethyl-; o-Dimethylbenzene; o-Methyltoluene; o-Xylol; 1,2-Dimethylbenzene; 1,2-Xylene; 3,4-Xylene; ortho-Xylene; NSC 60920; 2-Methyltoluene; UN 1307; 1,2-dimethyl-benzene ( o-xylene)
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Condensed phase thermochemistry data
Go To: Top, Phase change 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
DH - Eugene S. Domalski and Elizabeth D. Hearing
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔfH°liquid | -24.4 ± 1.1 | kJ/mol | Ccb | Prosen, Gilmont, et al., 1945 | Hf by Prosen, Johnson, et al., 1946; ALS |
Quantity | Value | Units | Method | Reference | Comment |
ΔcH°liquid | -4551.48 ± 0.50 | kJ/mol | Cm | Coops, Mulder, et al., 1946 | Reanalyzed by Cox and Pilcher, 1970, Original value = -4549.68 ± 0.50 kJ/mol; Corresponding ΔfHºliquid = -25.7 kJ/mol (simple calculation by NIST; no Washburn corrections); ALS |
ΔcH°liquid | -4552.9 ± 1.0 | kJ/mol | Ccb | Prosen, Gilmont, et al., 1945 | Hf by Prosen, Johnson, et al., 1946; Corresponding ΔfHºliquid = -24.4 kJ/mol (simple calculation by NIST; no Washburn corrections); ALS |
ΔcH°liquid | -4567.6 | kJ/mol | Ccb | Richards and Barry, 1915 | At 291 K; Corresponding ΔfHºliquid = -9.6 kJ/mol (simple calculation by NIST; no Washburn corrections); ALS |
ΔcH°liquid | -4581.4 | kJ/mol | Ccb | Richards and Jesse, 1910 | At 293 K; Corresponding ΔfHºliquid = 4.2 kJ/mol (simple calculation by NIST; no Washburn corrections); ALS |
Quantity | Value | Units | Method | Reference | Comment |
S°liquid | 246.02 | J/mol*K | N/A | Pitzer and Scott, 1943 | DH |
S°liquid | 248.1 | J/mol*K | N/A | Huffman, Parks, et al., 1930 | Extrapolation below 90 K, 60.79 J/mol*K.; DH |
Constant pressure heat capacity of liquid
Cp,liquid (J/mol*K) | Temperature (K) | Reference | Comment |
---|---|---|---|
187.653 | 298.15 | Fortier and Benson, 1979 | DH |
187.584 | 298.15 | Fortier and Benson, 1977 | DH |
206.7 | 347. | Swietoslawski and Zielenkiewicz, 1958 | Mean value 22 to 126 C.; DH |
187.0 | 298. | Kurbatov, 1947 | T = 15 to 132 C, mean Cp, three temperatures.; DH |
187.82 | 298.15 | Pitzer and Scott, 1943 | T = 14 to 301 K.; DH |
183.89 | 298.1 | Huffman, Parks, et al., 1930 | T = 90 to 295 K. Value is unsmoothed experimental datum.; DH |
182.4 | 303. | Willams and Daniels, 1924 | T = 303 to 348 K. Equation only.; DH |
Phase change 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:
TRC - Thermodynamics Research Center, NIST Boulder Laboratories, Chris Muzny director
BS - Robert L. Brown and Stephen E. Stein
AC - William E. Acree, Jr., James S. Chickos
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
DRB - Donald R. Burgess, Jr.
DH - Eugene S. Domalski and Elizabeth D. Hearing
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
Tboil | 417. ± 2. | K | AVG | N/A | Average of 50 out of 51 values; Individual data points |
Quantity | Value | Units | Method | Reference | Comment |
Tfus | 248. ± 2. | K | AVG | N/A | Average of 12 out of 13 values; Individual data points |
Quantity | Value | Units | Method | Reference | Comment |
Ttriple | 247.8 | K | N/A | Huffman, Parks, et al., 1930, 2 | Uncertainty assigned by TRC = 0.25 K; TRC |
Quantity | Value | Units | Method | Reference | Comment |
Tc | 631. ± 3. | K | AVG | N/A | Average of 11 out of 12 values; Individual data points |
Quantity | Value | Units | Method | Reference | Comment |
Pc | 37. ± 5. | bar | AVG | N/A | Average of 7 values; Individual data points |
Quantity | Value | Units | Method | Reference | Comment |
Vc | 0.370 | l/mol | N/A | Tsonopoulos and Ambrose, 1995 | |
Quantity | Value | Units | Method | Reference | Comment |
ρc | 2.70 ± 0.04 | mol/l | N/A | Tsonopoulos and Ambrose, 1995 | |
ρc | 2.699 | mol/l | N/A | Akhundov and Imanov, 1970 | Uncertainty assigned by TRC = 0.05 mol/l; TRC |
ρc | 2.710 | mol/l | N/A | Simon, 1957 | Uncertainty assigned by TRC = 0.04 mol/l; TRC |
Quantity | Value | Units | Method | Reference | Comment |
ΔvapH° | 42. ± 5. | kJ/mol | AVG | N/A | Average of 9 values; Individual data points |
Enthalpy of vaporization
ΔvapH (kJ/mol) | Temperature (K) | Method | Reference | Comment |
---|---|---|---|---|
36.24 | 417.6 | N/A | Majer and Svoboda, 1985 | |
41.1 | 348. | A | Stephenson and Malanowski, 1987 | Based on data from 333. to 419. K.; AC |
38.0 | 431. | A | Stephenson and Malanowski, 1987 | Based on data from 416. to 473. K.; AC |
36.7 | 486. | A | Stephenson and Malanowski, 1987 | Based on data from 471. to 571. K.; AC |
36.7 | 582. | A | Stephenson and Malanowski, 1987 | Based on data from 567. to 630. K.; AC |
39.8 | 401. | N/A | Castellari, Francesconi, et al., 1982 | Based on data from 386. to 416. K.; AC |
40.8 | 352. | MM | Willingham, Taylor, et al., 1945 | Based on data from 337. to 419. K. See also Forziati, Norris, et al., 1949.; AC |
45.0 | 288. | N/A | Pitzer and Scott, 1943 | Based on data from 273. to 323. K. See also Boublik, Fried, et al., 1984.; 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 |
---|---|---|---|---|---|
336.61 to 418.52 | 4.12928 | 1478.244 | -59.076 | Williamham, Taylor, et al., 1945 | Coefficents calculated by NIST from author's data. |
273. to 323. | 4.93755 | 1901.373 | -26.268 | Pitzer and Scott, 1943 | Coefficents calculated by NIST from author's data. |
Enthalpy of sublimation
ΔsubH (kJ/mol) | Temperature (K) | Method | Reference | Comment |
---|---|---|---|---|
60.1 | 248. | B | Hessler and Lichtenstein, 1986 | AC |
Enthalpy of fusion
ΔfusH (kJ/mol) | Temperature (K) | Reference | Comment |
---|---|---|---|
13.598 | 247.82 | Pitzer and Scott, 1943 | DH |
13.6 | 247.8 | Domalski and Hearing, 1996 | AC |
Entropy of fusion
ΔfusS (J/mol*K) | Temperature (K) | Reference | Comment |
---|---|---|---|
54.87 | 247.82 | Pitzer and Scott, 1943 | DH |
Enthalpy of phase transition
ΔHtrs (kJ/mol) | Temperature (K) | Initial Phase | Final Phase | Reference | Comment |
---|---|---|---|---|---|
0.031 | 208. | crystaline, II | crystaline, I | Huffman, Parks, et al., 1930 | DH |
13.037 | 247.8 | crystaline, I | liquid | Huffman, Parks, et al., 1930 | DH |
Entropy of phase transition
ΔStrs (J/mol*K) | Temperature (K) | Initial Phase | Final Phase | Reference | Comment |
---|---|---|---|---|---|
0.15 | 208. | crystaline, II | crystaline, I | Huffman, Parks, et al., 1930 | DH |
52.61 | 247.8 | crystaline, I | liquid | Huffman, Parks, et al., 1930 | DH |
References
Go To: Top, Condensed phase thermochemistry data, Phase change data, Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Prosen, Gilmont, et al., 1945
Prosen, E.J.; Gilmont, R.; Rossini, F.D.,
Heats of combustion of benzene, toluene, ethyl-benzene, o-xylene, m-xylene, p-xylene, n-propylbenzene, and styrene,
J. Res. NBS, 1945, 34, 65-70. [all data]
Prosen, Johnson, et al., 1946
Prosen, E.J.; Johnson, W.H.; Rossini, F.D.,
Heats of combustion and formation at 25°C of the alkylbenzenes through C10H14, and of the higher normal monoalkylbenzenes,
J. Res. NBS, 1946, 36, 455-461. [all data]
Coops, Mulder, et al., 1946
Coops, J.; Mulder, D.; Dienske, J.W.; Smittenberg, J.,
The heats of combustion of a number of hydrocarbons,
Rec. Trav. Chim. Pays/Bas, 1946, 65, 128. [all data]
Cox and Pilcher, 1970
Cox, J.D.; Pilcher, G.,
Thermochemistry of Organic and Organometallic Compounds, Academic Press, New York, 1970, 1-636. [all data]
Richards and Barry, 1915
Richards, T.W.; Barry, F.,
The heats of combustion of aromatic hydrocarbons and hexamethylene,
J. Am. Chem. Soc., 1915, 37, 993-1020. [all data]
Richards and Jesse, 1910
Richards, T.W.; Jesse, R.H., Jr.,
The heats of combustion of the octanes and xylenes,
J. Am. Chem. Soc., 1910, 32, 268-298. [all data]
Pitzer and Scott, 1943
Pitzer, K.S.; Scott, D.W.,
The thermodynamics and molecular structure of benzene and its methyl derivatives,
J. Am. Chem. Soc., 1943, 65, 803-829. [all data]
Huffman, Parks, et al., 1930
Huffman, H.M.; Parks, G.S.; Daniels, A.C.,
Thermal data on organic compounds. VII. The heat capacities, entropies and free energies of twelve aromatic hydrocarbons,
J. Am. Chem. Soc., 1930, 52, 1547-1558. [all data]
Fortier and Benson, 1979
Fortier, J.-L.; Benson, G.C.,
Heat capacities of some binary aromatic hydrocarbon mixtures containing benzene or toluene,
J. Chem. Eng. Data, 1979, 24(1), 34-37. [all data]
Fortier and Benson, 1977
Fortier, J.-L.; Benson, G.C.,
Excess heat capacities of binary mixtures of tetrachloromethane witlh some aromatic liquids at 298.15 K,
J. Chem. Thermodynam., 1977, 9, 1181-1188. [all data]
Swietoslawski and Zielenkiewicz, 1958
Swietoslawski, W.; Zielenkiewicz, A.,
Mean specific heats of binary positive azeotropes,
Bull. Acad. Pol. Sci. Ser. Sci. Chim., 1958, 6, 367-369. [all data]
Kurbatov, 1947
Kurbatov, V.Ya.,
Specific heat of liquids. I. Specific heat of benzenoid hydrocarbons,
Zhur. Obshch. Khim., 1947, 17, 1999-2003. [all data]
Willams and Daniels, 1924
Willams, J.W.; Daniels, F.,
The specific heats of certain organic liquids at elevated temperatures,
J. Am. Chem. Soc., 1924, 46, 903-917. [all data]
Huffman, Parks, et al., 1930, 2
Huffman, H.M.; Parks, G.S.; Daniels, A.C.,
Thermal Data on Organic Compounds: VII The Heat Capacities, Entropies and Free Energies of Twelve Aromatic Hydrocarbons,
J. Am. Chem. Soc., 1930, 52, 1547-58. [all data]
Tsonopoulos and Ambrose, 1995
Tsonopoulos, C.; Ambrose, D.,
Vapor-Liquid Critical Properties of Elements and Compounds. 3. Aromatic Hydrocarbons,
J. Chem. Eng. Data, 1995, 40, 547-558. [all data]
Akhundov and Imanov, 1970
Akhundov, T.S.; Imanov, Sh.Yu.,
Teplofiz. Svoistva Zhidk., 1970, 1970, 48-55. [all data]
Simon, 1957
Simon, M.,
Methods and Apparatus Used at the Bureau of Physicochemical Standards XV. Critical Constants and Straight-Line Diameters of Ten Hydrocarbons,
Bull. Soc. Chim. Belg., 1957, 66, 375-81. [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]
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]
Castellari, Francesconi, et al., 1982
Castellari, Carlo; Francesconi, Romolo; Comelli, Fabio,
Vapor-liquid equilibriums in binary systems containing 1,3-dioxolane at isobaric conditions. 3. Binary mixtures of 1,3-dioxolane with o-, m-, and p-xylenes,
J. Chem. Eng. Data, 1982, 27, 2, 156-158, https://doi.org/10.1021/je00028a017
. [all data]
Willingham, Taylor, et al., 1945
Willingham, C.B.; Taylor, W.J.; Pignocco, J.M.; Rossini, F.D.,
Vapor pressures and boiling points of some paraffin, alkylcyclopentane, alkylcyclohexane, and alkylbenzene hydrocarbons,
J. RES. NATL. BUR. STAN., 1945, 35, 3, 219-17, https://doi.org/10.6028/jres.035.009
. [all data]
Forziati, Norris, et al., 1949
Forziati, Alphonse F.; Norris, William R.; Rossini, Frederick D.,
Vapor pressures and boiling points of sixty API-NBS hydrocarbons,
J. RES. NATL. BUR. STAN., 1949, 43, 6, 555-17, https://doi.org/10.6028/jres.043.050
. [all data]
Boublik, Fried, et al., 1984
Boublik, T.; Fried, V.; Hala, E.,
The Vapour Pressures of Pure Substances: Selected Values of the Temperature Dependence of the Vapour Pressures of Some Pure Substances in the Normal and Low Pressure Region, 2nd ed., Elsevier, New York, 1984, 972. [all data]
Williamham, Taylor, et al., 1945
Williamham, C.B.; Taylor, W.J.; Pignocco, J.M.; Rossini, F.D.,
Vapor Pressures and Boiling Points of Some Paraffin, Alkylcyclopentane, Alkylcyclohexane, and Alkylbenzene Hydrocarbons,
J. Res. Natl. Bur. Stand. (U.S.), 1945, 35, 3, 219-244, https://doi.org/10.6028/jres.035.009
. [all data]
Hessler and Lichtenstein, 1986
Hessler, W.; Lichtenstein, W.,
Wiss. Zeitschr. Wilhelm-Pieck-Univ. Rostock, Naturwiss. Reihe, 1986, 35, 7, 27. [all data]
Domalski and Hearing, 1996
Domalski, Eugene S.; Hearing, Elizabeth D.,
Heat Capacities and Entropies of Organic Compounds in the Condensed Phase. Volume III,
J. Phys. Chem. Ref. Data, 1996, 25, 1, 1, https://doi.org/10.1063/1.555985
. [all data]
Notes
Go To: Top, Condensed phase thermochemistry data, Phase change data, References
- Symbols used in this document:
Cp,liquid Constant pressure heat capacity of liquid Pc Critical pressure S°liquid Entropy of liquid at standard conditions Tboil Boiling point Tc Critical temperature Tfus Fusion (melting) point Ttriple Triple point temperature Vc Critical volume ΔHtrs Enthalpy of phase transition ΔStrs Entropy of phase transition ΔcH°liquid Enthalpy of combustion of liquid at standard conditions ΔfH°liquid Enthalpy of formation of liquid at standard conditions ΔfusH Enthalpy of fusion ΔfusS Entropy of fusion ΔsubH Enthalpy of sublimation ΔvapH Enthalpy of vaporization ΔvapH° Enthalpy of vaporization at standard conditions ρc Critical density - Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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