Pentane, 2,3,4-trimethyl-
- Formula: C8H18
- Molecular weight: 114.2285
- IUPAC Standard InChIKey: RLPGDEORIPLBNF-UHFFFAOYSA-N
- CAS Registry Number: 565-75-3
- 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: 2,3,4-Trimethylpentane; (CH3)2CHCH(CH3)CH(CH3)2
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Condensed phase thermochemistry data
Go To: Top, 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 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 | -60.99 ± 0.40 | kcal/mol | Ccb | Prosen and Rossini, 1945 | ALS |
Quantity | Value | Units | Method | Reference | Comment |
ΔcH°liquid | -1306.28 ± 0.38 | kcal/mol | Ccb | Prosen and Rossini, 1945 | Corresponding ΔfHºliquid = -60.96 kcal/mol (simple calculation by NIST; no Washburn corrections); ALS |
Quantity | Value | Units | Method | Reference | Comment |
S°liquid | 78.709 | cal/mol*K | N/A | Pitzer and Scott, 1941 | DH |
Constant pressure heat capacity of liquid
Cp,liquid (cal/mol*K) | Temperature (K) | Reference | Comment |
---|---|---|---|
59.111 | 298.15 | Osborne and Ginnings, 1947 | T = 278 to 318 K.; DH |
58.850 | 293.79 | Pitzer and Scott, 1941 | T = 14 to 325 K. Value is unsmoothed experimental datum.; DH |
Phase change data
Go To: Top, Condensed phase thermochemistry 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 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
DH - Eugene S. Domalski and Elizabeth D. Hearing
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
Tboil | 386.8 ± 0.3 | K | AVG | N/A | Average of 18 values; Individual data points |
Quantity | Value | Units | Method | Reference | Comment |
Tfus | 163.8 ± 0.4 | K | AVG | N/A | Average of 10 out of 11 values; Individual data points |
Quantity | Value | Units | Method | Reference | Comment |
Ttriple | 163.63 | K | N/A | Pitzer and Scott, 1941, 2 | Uncertainty assigned by TRC = 0.12 K; measured in calorimeter, extrap. to 1/F=0; TRC |
Quantity | Value | Units | Method | Reference | Comment |
Tc | 566.4 ± 0.5 | K | N/A | Daubert, 1996 | |
Tc | 566.3 | K | N/A | Majer and Svoboda, 1985 | |
Tc | 566.34 | K | N/A | McMicking and Kay, 1965 | Uncertainty assigned by TRC = 0.5 K; TRC |
Quantity | Value | Units | Method | Reference | Comment |
Pc | 26.9 ± 0.4 | atm | N/A | Daubert, 1996 | |
Pc | 26.941 | atm | N/A | McMicking and Kay, 1965 | Uncertainty assigned by TRC = 0.4000 atm; TRC |
Quantity | Value | Units | Method | Reference | Comment |
Vc | 0.460 | l/mol | N/A | Daubert, 1996 | |
Quantity | Value | Units | Method | Reference | Comment |
ρc | 2.17 ± 0.04 | mol/l | N/A | Daubert, 1996 | |
ρc | 2.17 | mol/l | N/A | McMicking and Kay, 1965 | Uncertainty assigned by TRC = 0.04 mol/l; TRC |
Quantity | Value | Units | Method | Reference | Comment |
ΔvapH° | 9.039 | kcal/mol | N/A | Majer and Svoboda, 1985 | |
ΔvapH° | 9.01 ± 0.02 | kcal/mol | C | Hossenlopp and Scott, 1981 | AC |
ΔvapH° | 9.01 | kcal/mol | N/A | Reid, 1972 | AC |
ΔvapH° | 9.01 ± 0.02 | kcal/mol | C | Osborne and Ginnings, 1947, 2 | AC |
ΔvapH° | 9.011 | kcal/mol | C | Osborne and Ginnings, 1947 | ALS |
Enthalpy of vaporization
ΔvapH (kcal/mol) | Temperature (K) | Method | Reference | Comment |
---|---|---|---|---|
7.734 | 386.6 | N/A | Majer and Svoboda, 1985 | |
9.01 | 303. | A | Stephenson and Malanowski, 1987 | Based on data from 288. to 400. K.; AC |
9.35 | 274. | A | Stephenson and Malanowski, 1987 | Based on data from 223. to 289. K.; AC |
9.87 | 238. | IP,EB | Osborn and Douslin, 1974 | Based on data from 223. to 426. K.; AC |
9.51 | 263. | IP | Osborn and Douslin, 1974 | Based on data from 223. to 278. K.; AC |
8.77 | 325. | MM | Willingham, Taylor, et al., 1945 | Based on data from 310. to 388. K.; AC |
Enthalpy of vaporization
ΔvapH =
A exp(-βTr) (1 − Tr)β
ΔvapH =
Enthalpy of vaporization (at saturation pressure)
(kcal/mol)
Tr = reduced temperature (T / Tc)
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Temperature (K) | A (kcal/mol) | β | Tc (K) | Reference | Comment |
---|---|---|---|---|---|
298. to 414. | 12.84 | 0.2772 | 566.3 | Majer and Svoboda, 1985 |
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 |
---|---|---|---|---|---|
222.83 to 426.32 | 4.15060 | 1420.71 | -44.618 | Osborn and Douslin, 1974 | Coefficents calculated by NIST from author's data. |
309.72 to 387.53 | 3.97315 | 1315.084 | -55.624 | Williamham, Taylor, et al., 1945 |
Enthalpy of fusion
ΔfusH (kcal/mol) | Temperature (K) | Reference | Comment |
---|---|---|---|
2.215 | 163.63 | Pitzer and Scott, 1941 | DH |
2.22 | 163.6 | Domalski and Hearing, 1996 | AC |
Entropy of fusion
ΔfusS (cal/mol*K) | Temperature (K) | Reference | Comment |
---|---|---|---|
13.54 | 163.63 | Pitzer and Scott, 1941 | DH |
Reaction thermochemistry data
Go To: Top, Condensed phase thermochemistry data, 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 by: Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
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: C8H18 = C8H18
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | -1.25 ± 0.32 | kcal/mol | Ciso | Prosen and Rossini, 1945, 2 | liquid phase; Calculated from ΔHc |
References
Go To: Top, Condensed phase thermochemistry data, Phase change data, Reaction thermochemistry data, Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Prosen and Rossini, 1945
Prosen, E.J.; Rossini, F.D.,
Heats of combustion and formation of the paraffin hydrocarbons at 25° C,
J. Res. NBS, 1945, 263-267. [all data]
Pitzer and Scott, 1941
Pitzer, K.S.; Scott, D.W.,
The thermodynamics of branched-chain paraffins. The heat capacity, heat of fusion and vaporization, and entropy of 2,3,4-trimethylpentane,
J. Am. Chem. Soc., 1941, 63, 2419-2422. [all data]
Osborne and Ginnings, 1947
Osborne, N.S.; Ginnings, D.C.,
Measurements of heat of vaporization and heat capacity of a number of hydrocarbons,
J. Res. NBS, 1947, 39, 453-477. [all data]
Pitzer and Scott, 1941, 2
Pitzer, K.S.; Scott, D.W.,
The Thermodynamics of Branched-Chain Paraffins. The HEat Capacity, Heat of Fusion and Vaporization, and Entropy of 2,3,4-Trimethylpentane,
J. Am. Chem. Soc., 1941, 63, 2419-22. [all data]
Daubert, 1996
Daubert, T.E.,
Vapor-Liquid Critical Properties of Elements and Compounds. 5. Branched Alkanes and Cycloalkanes,
J. Chem. Eng. Data, 1996, 41, 365-372. [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]
McMicking and Kay, 1965
McMicking, J.H.; Kay, W.B.,
Vapor Pressures and Saturated Liquid and Vapor Densities of The Isomeric Heptanes and Isomeric Octanes,
Proc., Am. Pet. Inst., Sect. 3, 1965, 45, 75-90. [all data]
Hossenlopp and Scott, 1981
Hossenlopp, I.A.; Scott, D.W.,
Vapor heat capacities and enthalpies of vaporization of five alkane hydrocarbons,
J. Chem. Thermodyn., 1981, 13, 415-421. [all data]
Reid, 1972
Reid, Robert C.,
Handbook on vapor pressure and heats of vaporization of hydrocarbons and related compounds, R. C. Wilhort and B. J. Zwolinski, Texas A Research Foundation. College Station, Texas(1971). 329 pages.$10.00,
AIChE J., 1972, 18, 6, 1278-1278, https://doi.org/10.1002/aic.690180637
. [all data]
Osborne and Ginnings, 1947, 2
Osborne, Nathan S.; Ginnings, Defoe C.,
Measurements of heat of vaporization and heat capacity of a number of hydrocarbons,
J. RES. NATL. BUR. STAN., 1947, 39, 5, 453-17, https://doi.org/10.6028/jres.039.031
. [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]
Osborn and Douslin, 1974
Osborn, Ann G.; Douslin, Donald R.,
Vapor-pressure relations for 15 hydrocarbons,
J. Chem. Eng. Data, 1974, 19, 2, 114-117, https://doi.org/10.1021/je60061a022
. [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]
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]
Prosen and Rossini, 1945, 2
Prosen, E.J.; Rossini, F.D.,
Heats of isomerization of the 18 octanes,
J. Res. NBS, 1945, 34, 163-174. [all data]
Notes
Go To: Top, Condensed phase thermochemistry data, Phase change data, Reaction thermochemistry 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 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 ΔrH° Enthalpy 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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