Benzene, 1,3-dimethyl-
- Formula: C8H10
- Molecular weight: 106.1650
- IUPAC Standard InChIKey: IVSZLXZYQVIEFR-UHFFFAOYSA-N
- CAS Registry Number: 108-38-3
- 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: m-Xylene; m-Dimethylbenzene; m-Xylol; 1,3-Dimethylbenzene; 1,3-Xylene; 2,4-Xylene; m-Methyltoluene; meta-Xylene; NSC 61769; UN 1307; 1,3-dimethylbenzene (m-xylene)
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Gas phase thermochemistry data
Go To: Top, Phase change data, Reaction thermochemistry data, Mass spectrum (electron ionization), 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 | 4.12 ± 0.18 | kcal/mol | Ccb | Prosen, Johnson, et al., 1946 | ALS |
Quantity | Value | Units | Method | Reference | Comment |
S°gas | 85.60 ± 0.30 | cal/mol*K | N/A | Pitzer K.S., 1943 | GT |
Constant pressure heat capacity of gas
Cp,gas (cal/mol*K) | Temperature (K) | Reference | Comment |
---|---|---|---|
20.84 | 200. | Draeger, 1985 | Discrepancies with other statistically calculated values of S(T) and Cp(T) [ Pitzer K.S., 1943, Taylor W.J., 1946, Hastings S.H., 1957, Chao J., 1984] do not exceed 1.5 J/mol*K.; GT |
27.63 | 273.15 | ||
30.07 ± 0.1 | 298.15 | ||
30.26 | 300. | ||
39.94 | 400. | ||
48.49 | 500. | ||
55.64 | 600. | ||
61.59 | 700. | ||
66.59 | 800. | ||
70.79 | 900. | ||
74.38 | 1000. | ||
77.46 | 1100. | ||
80.09 | 1200. | ||
82.36 | 1300. | ||
84.32 | 1400. | ||
85.99 | 1500. |
Constant pressure heat capacity of gas
Cp,gas (cal/mol*K) | Temperature (K) | Reference | Comment |
---|---|---|---|
39.10 ± 0.40 | 393. | Taylor W.J., 1946 | Please also see Pitzer K.S., 1943.; GT |
42.40 ± 0.40 | 428. | ||
45.40 ± 0.40 | 463. |
Phase change data
Go To: Top, Gas phase thermochemistry data, Reaction thermochemistry data, Mass spectrum (electron ionization), 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 | 412.3 ± 0.3 | K | AVG | N/A | Average of 39 out of 42 values; Individual data points |
Quantity | Value | Units | Method | Reference | Comment |
Tfus | 225. ± 4. | K | AVG | N/A | Average of 8 values; Individual data points |
Quantity | Value | Units | Method | Reference | Comment |
Ttriple | 219.6 | K | N/A | Huffman, Parks, et al., 1930 | Uncertainty assigned by TRC = 0.3 K; TRC |
Quantity | Value | Units | Method | Reference | Comment |
Tc | 618. ± 4. | K | AVG | N/A | Average of 9 values; Individual data points |
Quantity | Value | Units | Method | Reference | Comment |
Pc | 34.9 ± 0.4 | atm | N/A | Tsonopoulos and Ambrose, 1995 | |
Pc | 34.949 | atm | N/A | Ambrose, 1987 | Uncertainty assigned by TRC = 0.05 atm; TRC |
Pc | 34.95 | atm | N/A | Ambrose, Broderick, et al., 1967 | Uncertainty assigned by TRC = 0.06 atm; TRC |
Pc | 33.0000 | atm | N/A | Glaser and Ruland, 1957 | Uncertainty assigned by TRC = 1.5000 atm; TRC |
Pc | 34.64 | atm | N/A | Altschul, 1893 | Uncertainty assigned by TRC = 0.0387 atm; TRC |
Quantity | Value | Units | Method | Reference | Comment |
Vc | 0.375 | l/mol | N/A | Tsonopoulos and Ambrose, 1995 | |
Quantity | Value | Units | Method | Reference | Comment |
ρc | 2.67 ± 0.04 | mol/l | N/A | Tsonopoulos and Ambrose, 1995 | |
ρc | 2.684 | mol/l | N/A | Akhundov and Asadullaeva, 1968 | Uncertainty assigned by TRC = 0.05 mol/l; TRC |
Quantity | Value | Units | Method | Reference | Comment |
ΔvapH° | 10. ± 1. | kcal/mol | AVG | N/A | Average of 8 values; Individual data points |
Enthalpy of vaporization
ΔvapH (kcal/mol) | Temperature (K) | Method | Reference | Comment |
---|---|---|---|---|
8.523 | 412.3 | N/A | Majer and Svoboda, 1985 | |
9.37 | 375. | N/A | Swiatek and Malanowski, 2002 | Based on data from 360. to 410. K.; AC |
9.73 | 342. | N/A | Park and Gmehling, 1989 | Based on data from 327. to 412. K.; AC |
10.7 | 282. | A | Stephenson and Malanowski, 1987 | Based on data from 267. to 301. K.; AC |
8.96 | 427. | A | Stephenson and Malanowski, 1987 | Based on data from 412. to 462. K.; AC |
8.70 | 476. | A | Stephenson and Malanowski, 1987 | Based on data from 461. to 554. K.; AC |
8.65 | 565. | A | Stephenson and Malanowski, 1987 | Based on data from 550. to 617. K.; AC |
9.66 | 346. | MM | Stephenson and Malanowski, 1987 | Based on data from 331. to 415. K. See also Willingham, Taylor, et al., 1945 and Forziati, Norris, et al., 1949.; AC |
9.25 | 395. | N/A | Machat, 1983 | Based on data from 380. to 411. K.; AC |
10.3 | 288. | N/A | Pitzer and Scott, 1943 | Based on data from 273. to 333. K. See also Boublik, Fried, et al., 1984.; AC |
Antoine Equation Parameters
log10(P) = A − (B / (T + C))
P = vapor pressure (atm)
T = temperature (K)
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Temperature (K) | A | B | C | Reference | Comment |
---|---|---|---|---|---|
332.4 to 413.19 | 4.13036 | 1463.218 | -57.991 | Williamham, Taylor, et al., 1945 | Coefficents calculated by NIST from author's data. |
273. to 333. | 5.08628 | 1996.545 | -14.772 | Pitzer and Scott, 1943 | Coefficents calculated by NIST from author's data. |
Enthalpy of fusion
ΔfusH (kcal/mol) | Temperature (K) | Reference | Comment |
---|---|---|---|
2.7651 | 225.27 | Pitzer and Scott, 1943 | DH |
2.770 | 225.3 | Domalski and Hearing, 1996 | AC |
Entropy of fusion
ΔfusS (cal/mol*K) | Temperature (K) | Reference | Comment |
---|---|---|---|
12.28 | 225.27 | Pitzer and Scott, 1943 | DH |
Enthalpy of phase transition
ΔHtrs (kcal/mol) | Temperature (K) | Initial Phase | Final Phase | Reference | Comment |
---|---|---|---|---|---|
0.0497 | 166. | crystaline, II | crystaline, I | Huffman, Parks, et al., 1930, 2 | DH |
2.7349 | 219.6 | crystaline, I | liquid | Huffman, Parks, et al., 1930, 2 | DH |
Entropy of phase transition
ΔStrs (cal/mol*K) | Temperature (K) | Initial Phase | Final Phase | Reference | Comment |
---|---|---|---|---|---|
0.299 | 166. | crystaline, II | crystaline, I | Huffman, Parks, et al., 1930, 2 | DH |
12.45 | 219.6 | crystaline, I | liquid | Huffman, Parks, et al., 1930, 2 | DH |
Reaction thermochemistry data
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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:
M - Michael M. Meot-Ner (Mautner) and Sharon G. Lias
B - John E. Bartmess
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.
Individual Reactions
By formula: C3H9Si+ + C8H10 = (C3H9Si+ • C8H10)
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 29.0 | kcal/mol | PHPMS | Wojtyniak and Stone, 1986 | gas phase; switching reaction,Thermochemical ladder((CH3)3Si+)C6H6, Entropy change calculated or estimated; M |
Quantity | Value | Units | Method | Reference | Comment |
ΔrS° | 35.1 | cal/mol*K | N/A | Wojtyniak and Stone, 1986 | gas phase; switching reaction,Thermochemical ladder((CH3)3Si+)C6H6, Entropy change calculated or estimated; M |
Free energy of reaction
ΔrG° (kcal/mol) | T (K) | Method | Reference | Comment |
---|---|---|---|---|
12.7 | 468. | PHPMS | Wojtyniak and Stone, 1986 | gas phase; switching reaction,Thermochemical ladder((CH3)3Si+)C6H6, Entropy change calculated or estimated; M |
By formula: C9H12+ + C8H10 = (C9H12+ • C8H10)
Bond type: Charge transfer bond (positive ion)
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 14.3 | kcal/mol | PHPMS | Meot-Ner (Mautner), Hamlet, et al., 1978 | gas phase; Entropy change calculated or estimated; M |
Quantity | Value | Units | Method | Reference | Comment |
ΔrS° | 27. | cal/mol*K | N/A | Meot-Ner (Mautner), Hamlet, et al., 1978 | gas phase; Entropy change calculated or estimated; M |
Free energy of reaction
ΔrG° (kcal/mol) | T (K) | Method | Reference | Comment |
---|---|---|---|---|
6.2 | 300. | PHPMS | Meot-Ner (Mautner), Hamlet, et al., 1978 | gas phase; Entropy change calculated or estimated; M |
C8H9- + =
By formula: C8H9- + H+ = C8H10
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 381.0 ± 2.6 | kcal/mol | G+TS | Caldwell and Bartmess | gas phase; value altered from reference due to change in acidity scale; B |
Quantity | Value | Units | Method | Reference | Comment |
ΔrG° | 373.9 ± 2.5 | kcal/mol | IMRE | Caldwell and Bartmess | gas phase; value altered from reference due to change in acidity scale; B |
By formula: Cl- + C8H10 = (Cl- • C8H10)
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrG° | 3.90 | kcal/mol | TDEq | French, Ikuta, et al., 1982 | gas phase; B |
Free energy of reaction
ΔrG° (kcal/mol) | T (K) | Method | Reference | Comment |
---|---|---|---|---|
4.4 | 300. | PHPMS | French, Ikuta, et al., 1982 | gas phase; M |
Mass spectrum (electron ionization)
Go To: Top, Gas phase thermochemistry data, Phase change 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 compiled by: NIST Mass Spectrometry Data Center, William E. Wallace, director
Spectrum
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Additional Data
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Owner | NIST Mass Spectrometry Data Center Collection (C) 2014 copyright by the U.S. Secretary of Commerce on behalf of the United States of America. All rights reserved. |
---|---|
Origin | NIST Mass Spectrometry Data Center, 1998. |
NIST MS number | 291455 |
References
Go To: Top, Gas phase thermochemistry data, Phase change data, Reaction thermochemistry data, Mass spectrum (electron ionization), Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
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]
Pitzer K.S., 1943
Pitzer K.S.,
The thermodynamics and molecular structure of benzene and its methyl derivatives,
J. Am. Chem. Soc., 1943, 65, 803-829. [all data]
Draeger, 1985
Draeger, J.A.,
The methylbenzenes II. Fundamental vibrational shifts, statistical thermodynamic functions, and properties of formation,
J. Chem. Thermodyn., 1985, 17, 263-275. [all data]
Taylor W.J., 1946
Taylor W.J.,
Heats, equilibrium constants, and free energies of formation of the alkylbenzenes,
J. Res. Nat. Bur. Stand., 1946, 37, 95-122. [all data]
Hastings S.H., 1957
Hastings S.H.,
Thermodynamic properties of selected methylbenzenes from 0 to 1000 K,
J. Phys. Chem., 1957, 61, 730-735. [all data]
Chao J., 1984
Chao J.,
Chemical thermodynamic properties of toluene, o-, m- and p-xylenes,
Thermochim. Acta, 1984, 72, 323-334. [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, 1547-58. [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]
Ambrose, 1987
Ambrose, D.,
Vapor Pressures of Some Aromatic Hydrocarbons,
J. Chem. Thermodyn., 1987, 19, 1007. [all data]
Ambrose, Broderick, et al., 1967
Ambrose, D.; Broderick, B.E.; Townsend, R.,
The Vapour Pressures above the Normal Boiling Point and the Critical Pressures of Some Aromatic Hydrocarbons,
J. Chem. Soc. , 1967, 1967, 1967, 633-41. [all data]
Glaser and Ruland, 1957
Glaser, F.; Ruland, H.,
Untersuchungsen über dampfdruckkurven und kritische daten einiger technisch wichtiger organischer substanzen,
Chem. Ing. Techn., 1957, 29, 772. [all data]
Altschul, 1893
Altschul, M.,
The critical values of some organic compounds,
Z. Phys. Chem., Stoechiom. Verwandtschaftsl., 1893, 11, 577. [all data]
Akhundov and Asadullaeva, 1968
Akhundov, T.S.; Asadullaeva, N.N.,
Specific volumes of m-xylene near the critical point,
Izv. Vyssh. Uchebn. Zaved., Neft Gaz, 1968, 11, 6, 836. [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]
Swiatek and Malanowski, 2002
Swiatek, Barbara E.; Malanowski, Stanislaw K.,
Vapor-Liquid Equilibrium in m -Xylene + Cyclohexanol at 19.99 and 94.93 kPa,
J. Chem. Eng. Data, 2002, 47, 3, 478-481, https://doi.org/10.1021/je010246z
. [all data]
Park and Gmehling, 1989
Park, So Jin; Gmehling, Juergen,
Isobaric vapor-liquid equilibrium data for the binary systems 1,3,5-trimethylbenzene/N-formylmorpholine and m-xylene/N-formylmorpholine,
J. Chem. Eng. Data, 1989, 34, 4, 399-401, https://doi.org/10.1021/je00058a008
. [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]
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]
Machat, 1983
Machat, V.,
, Thesis, Utzcht, Prague, 1983. [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]
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]
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]
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, 1547-1558. [all data]
Wojtyniak and Stone, 1986
Wojtyniak, A.C.M.; Stone, A.J.,
A High-Pressure Mass Spectrometric Study of the Bonding of Trimethylsilylium to Oxygen and Aromatic Bases,
Can. J. Chem., 1986, 74, 59. [all data]
Meot-Ner (Mautner), Hamlet, et al., 1978
Meot-Ner (Mautner), M.; Hamlet, P.; Hunter, E.P.; Field, F.H.,
Bonding Energies in Association Ions of Aromatic Molecules. Correlations with Ionization Energies,
J. Am. Chem. Soc., 1978, 100, 17, 5466, https://doi.org/10.1021/ja00485a034
. [all data]
Caldwell and Bartmess
Caldwell, G.; Bartmess, J.E.,
, Unpublished results. [all data]
French, Ikuta, et al., 1982
French, M.A.; Ikuta, S.; Kebarle, P.,
Hydrogen bonding of O-H and C-H hydrogen donors to Cl-. Results from mass spectrometric measurement of the ion-molecule equilibria RH + Cl- = RHCl-,
Can. J. Chem., 1982, 60, 1907. [all data]
Notes
Go To: Top, Gas phase thermochemistry data, Phase change data, Reaction thermochemistry data, Mass spectrum (electron ionization), References
- Symbols used in this document:
Cp,gas Constant pressure heat capacity of gas Pc Critical pressure S°gas Entropy of gas at standard conditions T Temperature 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 ΔfH°gas Enthalpy of formation of gas at standard conditions ΔfusH Enthalpy of fusion ΔfusS Entropy of fusion ΔrG° Free energy of reaction at standard conditions ΔrH° Enthalpy of reaction at standard conditions ΔrS° Entropy of reaction at standard conditions 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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