Neopentane
- Formula: C5H12
- Molecular weight: 72.1488
- IUPAC Standard InChIKey: CRSOQBOWXPBRES-UHFFFAOYSA-N
- CAS Registry Number: 463-82-1
- 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: Propane, 2,2-dimethyl-; tert-Pentane; Tetramethylcarbon; Tetramethylmethane; 1,1,1-Trimethylethane; 2,2-Dimethylpropane; Neo-C5H12; UN 2044; Dimethylpropane
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Gas phase 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 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 | -167.9 ± 0.63 | kJ/mol | Ccb | Good, 1970 | ALS |
ΔfH°gas | -168.5 ± 1.0 | kJ/mol | Cm | Pilcher and Chadwick, 1967 | ALS |
ΔfH°gas | -166.0 ± 1.0 | kJ/mol | Ccb | Prosen and Rossini, 1945 | ALS |
Quantity | Value | Units | Method | Reference | Comment |
ΔcH°gas | -3514.1 ± 0.96 | kJ/mol | Cm | Pilcher and Chadwick, 1967 | Corresponding ΔfHºgas = -168.5 kJ/mol (simple calculation by NIST; no Washburn corrections); ALS |
Constant pressure heat capacity of gas
Cp,gas (J/mol*K) | Temperature (K) | Reference | Comment |
---|---|---|---|
120.82 ± 0.25 | 298.15 | Hossenlopp I.A., 1981 | GT |
129.58 ± 0.26 | 323.15 | ||
138.41 ± 0.28 | 348.15 | ||
147.06 ± 0.29 | 373.15 | ||
155.46 ± 0.31 | 398.15 | ||
163.52 ± 0.32 | 423.15 | ||
171.46 ± 0.34 | 448.15 | ||
178.95 ± 0.36 | 473.15 | ||
186.42 ± 0.37 | 498.15 | ||
193.38 ± 0.39 | 523.15 |
Constant pressure heat capacity of gas
Cp,gas (J/mol*K) | Temperature (K) | Reference | Comment |
---|---|---|---|
80.54 | 200. | Scott D.W., 1974 | Recommended values were obtained from the consistent correlation scheme for alkanes [ Scott D.W., 1974, 2, Scott D.W., 1974]. This approach gives a better agreement with experimental data than the statistical thermodynamics calculation [ Pitzer K.S., 1946].; GT |
111.63 | 273.15 | ||
120.83 ± 0.25 | 298.15 | ||
121.55 | 300. | ||
155.98 | 400. | ||
186.98 | 500. | ||
214.64 | 600. | ||
238.91 | 700. | ||
261.08 | 800. | ||
280.33 | 900. | ||
297.90 | 1000. | ||
313.38 | 1100. | ||
327.19 | 1200. | ||
338.90 | 1300. | ||
351.46 | 1400. | ||
359.82 | 1500. |
Condensed phase thermochemistry data
Go To: Top, Gas 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 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 | -190.3 ± 0.63 | kJ/mol | Ccb | Good, 1970 | ALS |
ΔfH°liquid | -188.2 ± 1.0 | kJ/mol | Ccb | Prosen and Rossini, 1945 | ALS |
Quantity | Value | Units | Method | Reference | Comment |
ΔcH°liquid | -3492.4 ± 0.59 | kJ/mol | Ccb | Good, 1970 | Reanalyzed by Pedley, Naylor, et al., 1986, Original value = -3492.2 ± 0.50 kJ/mol; Corresponding ΔfHºliquid = -190.1 kJ/mol (simple calculation by NIST; no Washburn corrections); ALS |
ΔcH°liquid | -3494.4 ± 1.0 | kJ/mol | Ccb | Prosen and Rossini, 1945 | Corresponding ΔfHºliquid = -188.2 kJ/mol (simple calculation by NIST; no Washburn corrections); ALS |
Quantity | Value | Units | Method | Reference | Comment |
S°liquid | 216.81 | J/mol*K | N/A | Enokida, Shinoda, et al., 1969 | At normal boiling point.; DH |
S°liquid | 218.8 | J/mol*K | N/A | Aston and Messerly, 1936 | DH |
Constant pressure heat capacity of liquid
Cp,liquid (J/mol*K) | Temperature (K) | Reference | Comment |
---|---|---|---|
153.09 | 259.93 | Enokida, Shinoda, et al., 1969 | T = 4 to 260 K. Value is unsmoothed experimental datum.; DH |
163.89 | 278.92 | Aston and Messerly, 1936 | T = 13 to 283 K. Value is unsmoothed experimental datum.; DH |
Phase change data
Go To: Top, Gas phase thermochemistry data, 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:
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
CAL - James S. Chickos, William E. Acree, Jr., Joel F. Liebman, Students of Chem 202 (Introduction to the Literature of Chemistry), University of Missouri -- St. Louis
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
Tboil | 282.6 ± 0.5 | K | AVG | N/A | Average of 17 values; Individual data points |
Quantity | Value | Units | Method | Reference | Comment |
Tfus | 255. ± 3. | K | AVG | N/A | Average of 8 values; Individual data points |
Quantity | Value | Units | Method | Reference | Comment |
Ttriple | 256.76 | K | N/A | Enokido, Shinoda, et al., 1969 | Crystal phase 1 phase; Uncertainty assigned by TRC = 0.02 K; TRC |
Ttriple | 256.77 | K | N/A | Streiff, 1964 | Crystal phase 1 phase; Uncertainty assigned by TRC = 0.03 K; TRC |
Ttriple | 256.53 | K | N/A | Aston and Messerly, 1936, 2 | Crystal phase 1 phase; Uncertainty assigned by TRC = 0.02 K; TRC |
Quantity | Value | Units | Method | Reference | Comment |
Tc | 433.8 ± 0.1 | K | N/A | Daubert, 1996 | |
Tc | 433.8 | K | N/A | Majer and Svoboda, 1985 | |
Tc | 433.8 | K | N/A | Dawson, Silberberg, et al., 1973 | Uncertainty assigned by TRC = 0.2 K; TRC |
Tc | 433.75 | K | N/A | Partington, Rowlinson, et al., 1960 | Uncertainty assigned by TRC = 0.1 K; Visual, THg; TRC |
Tc | 433.75 | K | N/A | Beattie, Douslin, et al., 1951 | Uncertainty assigned by TRC = 0.2 K; TRC |
Quantity | Value | Units | Method | Reference | Comment |
Pc | 32.0 ± 0.1 | bar | N/A | Daubert, 1996 | |
Pc | 31.963 | bar | N/A | Dawson, Silberberg, et al., 1973 | Uncertainty assigned by TRC = 0.1013 bar; TRC |
Pc | 31.99 | bar | N/A | Beattie, Douslin, et al., 1951 | Uncertainty assigned by TRC = 0.2027 bar; TRC |
Quantity | Value | Units | Method | Reference | Comment |
Vc | 0.307 | l/mol | N/A | Daubert, 1996 | |
Vc | 0.304 | l/mol | N/A | Beattie, Douslin, et al., 1951 | Uncertainty assigned by TRC = 0.004 l/mol; TRC |
Quantity | Value | Units | Method | Reference | Comment |
ρc | 3.26 ± 0.01 | mol/l | N/A | Daubert, 1996 | |
ρc | 3.214 | mol/l | N/A | Dawson, Silberberg, et al., 1973 | Uncertainty assigned by TRC = 0.03 mol/l; TRC |
Quantity | Value | Units | Method | Reference | Comment |
ΔvapH° | 22.39 | kJ/mol | N/A | Majer and Svoboda, 1985 | |
ΔvapH° | 21.8 | kJ/mol | C | Hossenlopp and Scott, 1981 | AC |
ΔvapH° | 21.85 | kJ/mol | N/A | Reid, 1972 | AC |
ΔvapH° | 22.4 ± 0.59 | kJ/mol | V | Good, 1970 | ALS |
Enthalpy of vaporization
ΔvapH (kJ/mol) | Temperature (K) | Method | Reference | Comment |
---|---|---|---|---|
22.74 | 282.7 | N/A | Majer and Svoboda, 1985 | |
22.753 | 282.61 | N/A | Aston and Messerly, 1936 | P = 101.325 kPa; DH |
24.3 | 272. | N/A | Höpfner, Parekh, et al., 2010 | Based on data from 257. to 293. K. See also Boublik, Fried, et al., 1984.; AC |
24.0 | 283. | A | Stephenson and Malanowski, 1987 | Based on data from 268. to 313. K.; AC |
23.1 | 327. | A | Stephenson and Malanowski, 1987 | Based on data from 312. to 385. K.; AC |
23.1 | 397. | A | Stephenson and Malanowski, 1987 | Based on data from 382. to 433. K.; AC |
22.2 | 290. | N/A | Das, Reed, et al., 1977 | AC |
19.5 | 330. | N/A | Das, Reed, et al., 1977 | AC |
16.2 | 370. | N/A | Das, Reed, et al., 1977 | AC |
11.1 | 410. | N/A | Das, Reed, et al., 1977 | AC |
22.8 | 358. | N/A | Dawson, Silberberg, et al., 1973 | Based on data from 343. to 433. K. See also Boublik, Fried, et al., 1984.; AC |
22.8 ± 0.1 | 283. | N/A | Aston and Messerly, 1936 | AC |
Enthalpy of vaporization
ΔvapH =
A exp(-βTr) (1 − Tr)β
ΔvapH =
Enthalpy of vaporization (at saturation pressure)
(kJ/mol)
Tr = reduced temperature (T / Tc)
View plot Requires a JavaScript / HTML 5 canvas capable browser.
Temperature (K) | A (kJ/mol) | β | Tc (K) | Reference | Comment |
---|---|---|---|---|---|
264. to 303. | 36.76 | 0.2813 | 433.8 | Majer and Svoboda, 1985 |
Entropy of vaporization
ΔvapS (J/mol*K) | Temperature (K) | Reference | Comment |
---|---|---|---|
80.50 | 282.61 | Aston and Messerly, 1936 | P; DH |
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 |
---|---|---|---|---|---|
205.7 to 293.16 | 3.28533 | 695.152 | -70.679 | Hopfner, Parekh, et al., 1975 | Coefficents calculated by NIST from author's data. |
268.02 to 313.20 | 3.86373 | 950.318 | -36.329 | Osborn and Douslin, 1974 | Coefficents calculated by NIST from author's data. |
343. to 433. | 4.61616 | 1478.868 | 41.256 | Dawson, Silberberg, et al., 1973 | Coefficents calculated by NIST from author's data. |
Enthalpy of sublimation
ΔsubH (kJ/mol) | Temperature (K) | Method | Reference | Comment |
---|---|---|---|---|
28.2 | 241. | N/A | Stephenson and Malanowski, 1987 | Based on data from 223. to 256. K.; AC |
23.9 | 210. | A | Stull, 1947 | Based on data from 171. to 249. K.; AC |
Enthalpy of fusion
ΔfusH (kJ/mol) | Temperature (K) | Reference | Comment |
---|---|---|---|
3.26 | 256.5 | Domalski and Hearing, 1996 | AC |
Entropy of fusion
ΔfusS (J/mol*K) | Temperature (K) | Reference | Comment |
---|---|---|---|
18.41 | 140. | Domalski and Hearing, 1996 | CAL |
12.69 | 256.5 |
Enthalpy of phase transition
ΔHtrs (kJ/mol) | Temperature (K) | Initial Phase | Final Phase | Reference | Comment |
---|---|---|---|---|---|
2.630 | 140.5 | crystaline, II | crystaline, I | Chang and Westrum, 1970 | DH |
3.096 | 256.76 | crystaline, I | liquid | Chang and Westrum, 1970 | DH |
2.6305 | 140. to 142. | crystaline, II | crystaline, I | Enokida, Shinoda, et al., 1969 | DH |
3.0962 | 256.76 | crystaline, I | liquid | Enokida, Shinoda, et al., 1969 | DH |
2.577 | 140.0 | crystaline, II | crystaline, I | Aston and Messerly, 1936 | DH |
3.255 | 256.53 | crystaline, I | liquid | Aston and Messerly, 1936 | DH |
Entropy of phase transition
ΔStrs (J/mol*K) | Temperature (K) | Initial Phase | Final Phase | Reference | Comment |
---|---|---|---|---|---|
18.70 | 140.5 | crystaline, II | crystaline, I | Chang and Westrum, 1970 | DH |
12.05 | 256.76 | crystaline, I | liquid | Chang and Westrum, 1970 | DH |
18.70 | 140. to 142. | crystaline, II, Second | crystaline, I, order transition, 140 to 142 K | Enokida, Shinoda, et al., 1969 | DH |
12.06 | 256.76 | crystaline, I | liquid | Enokida, Shinoda, et al., 1969 | DH |
18.41 | 140.0 | crystaline, II | crystaline, I | Aston and Messerly, 1936 | DH |
12.68 | 256.53 | crystaline, I | liquid | Aston and Messerly, 1936 | DH |
References
Go To: Top, Gas phase thermochemistry data, 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.
Good, 1970
Good, W.D.,
The enthalpies of combustion and formation of the isomeric pentanes,
J. Chem. Thermodyn., 1970, 2, 237-244. [all data]
Pilcher and Chadwick, 1967
Pilcher, G.; Chadwick, J.D.M.,
Measurements of heats of combustion by flame calorimetry. Part 4.-n-Pentane, isopentane, neopentane,
Trans. Faraday Soc., 1967, 63, 2357-2361. [all data]
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]
Hossenlopp I.A., 1981
Hossenlopp I.A.,
Vapor heat capacities and enthalpies of vaporization of five alkane hydrocarbons,
J. Chem. Thermodyn., 1981, 13, 415-421. [all data]
Scott D.W., 1974
Scott D.W.,
Chemical Thermodynamic Properties of Hydrocarbons and Related Substances. Properties of the Alkane Hydrocarbons, C1 through C10 in the Ideal Gas State from 0 to 1500 K. U.S. Bureau of Mines, Bulletin 666, 1974. [all data]
Scott D.W., 1974, 2
Scott D.W.,
Correlation of the chemical thermodynamic properties of alkane hydrocarbons,
J. Chem. Phys., 1974, 60, 3144-3165. [all data]
Pitzer K.S., 1946
Pitzer K.S.,
The entropies and related properties of branched paraffin hydrocarbons,
Chem. Rev., 1946, 39, 435-447. [all data]
Pedley, Naylor, et al., 1986
Pedley, J.B.; Naylor, R.D.; Kirby, S.P.,
Thermochemical Data of Organic Compounds, Chapman and Hall, New York, 1986, 1-792. [all data]
Enokida, Shinoda, et al., 1969
Enokida, H.; Shinoda, T.; Mashiko, Y.,
Thermodynamic properties of neopentane from 4K to the melting point and comparison with spectroscopic data,
Bull. Chem. Soc. Japan, 1969, 42, 84-91. [all data]
Aston and Messerly, 1936
Aston, J.G.; Messerly, G.H.,
Heat capacities and entropies of organic compounds. II. Thermal and vapor pressure data for tetramethylmethane from 13.22°K to the boiling point. The entropy from its Raman spectrum,
J. Am. Chem. Soc., 1936, 58, 2354-2361. [all data]
Enokido, Shinoda, et al., 1969
Enokido, H.; Shinoda, T.; Mashiko, Y.-I.,
Thermodynamic Properties of Neopentane from 4 K to the Melting Point and Comparison with Spectroscopic Data,
Bull. Chem. Soc. Jpn., 1969, 42, 84. [all data]
Streiff, 1964
Streiff, A.J.,
, Am. Pet. Inst. Res. Proj. 58B Unpublished, 1964. [all data]
Aston and Messerly, 1936, 2
Aston, J.G.; Messerly, G.H.,
Heat Capacities and Entropies of Organic Compounds II. Thermal and Vapor Pressure Data for Tetramethylmethane from 13.22K to the Boiling Point. The Entropy from its Raman Spectrum,
J. Am. Chem. Soc., 1936, 58, 2354. [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]
Dawson, Silberberg, et al., 1973
Dawson, Perry P.; Silberberg, I. Harold; McKetta, John J.,
Volumetric behavior, vapor pressures, and critical properties of neopentane,
J. Chem. Eng. Data, 1973, 18, 1, 7-15, https://doi.org/10.1021/je60056a007
. [all data]
Partington, Rowlinson, et al., 1960
Partington, E.J.; Rowlinson, J.S.; Weston, J.F.,
The Gas-Liquid Critical Temperatures of Binary Mixtures. Part 1.,
Trans. Faraday Soc., 1960, 56, 479. [all data]
Beattie, Douslin, et al., 1951
Beattie, J.A.; Douslin, D.R.; Levine, S.W.,
The vapor pressure and critical constants of neopentane.,
J. Chem. Phys., 1951, 19, 948. [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]
Höpfner, Parekh, et al., 2010
Höpfner, A.; Parekh, N.; Hörner, Ch.; Abdel-Hamid, A.,
Der Dampfdruck-Isotopie-Effekt von deuterierten Neopentanen,
Berichte der Bunsengesellschaft für physikalische Chemie, 2010, 79, 2, 216-222, https://doi.org/10.1002/bbpc.19750790217
. [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]
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]
Das, Reed, et al., 1977
Das, Tarun R.; Reed, Charles O.; Eubank, Philip T.,
PVT surface and thermodynamic properties of isopentane,
J. Chem. Eng. Data, 1977, 22, 1, 9-15, https://doi.org/10.1021/je60072a015
. [all data]
Hopfner, Parekh, et al., 1975
Hopfner, A.; Parekh, N.; Horner, Ch.; Abdel-Hamid, A.,
Der Dampfdruck-Isotopie-Effekt von deuterierten Neopentanen,
Ber. Bunsen-Ges. Phys. Chem., 1975, 79, 2, 216-222, https://doi.org/10.1002/bbpc.19750790217
. [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]
Stull, 1947
Stull, Daniel R.,
Vapor Pressure of Pure Substances. Organic and Inorganic Compounds,
Ind. Eng. Chem., 1947, 39, 4, 517-540, https://doi.org/10.1021/ie50448a022
. [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]
Chang and Westrum, 1970
Chang, E.T.; Westrum,
E.F., Heat capacities and thermodynamic properties of globular molecules. XV. The binary system tetramethylmethane-tetrachloromethane,
J. Phys. Chem., 1970, 74, 2528-2538. [all data]
Notes
Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change data, References
- Symbols used in this document:
Cp,gas Constant pressure heat capacity of gas 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°gas Enthalpy of combustion of gas at standard conditions ΔcH°liquid Enthalpy of combustion of liquid at standard conditions ΔfH°gas Enthalpy of formation of gas 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 ΔvapS Entropy of vaporization ρc Critical density - Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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