Cyclopentane, 1,1-dimethyl-
- Formula: C7H14
- Molecular weight: 98.1861
- IUPAC Standard InChIKey: QWHNJUXXYKPLQM-UHFFFAOYSA-N
- CAS Registry Number: 1638-26-2
- 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: Gem-Dimethylcyclopentane; 1,1-Dimethylcyclopentane
- Permanent link for this species. Use this link for bookmarking this species for future reference.
- Information on this page:
- Other data available:
- 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.
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 | -41.14 ± 0.27 | kcal/mol | Cm | Johnson, Prosen, et al., 1949 | ALS |
Quantity | Value | Units | Method | Reference | Comment |
ΔcH°liquid | -1095.44 ± 0.25 | kcal/mol | Cm | Johnson, Prosen, et al., 1949 | Corresponding ΔfHºliquid = -41.12 kcal/mol (simple calculation by NIST; no Washburn corrections); ALS |
Quantity | Value | Units | Method | Reference | Comment |
S°liquid | 63.339 | cal/mol*K | N/A | Gross, Oliver, et al., 1953 | DH |
Constant pressure heat capacity of liquid
Cp,liquid (cal/mol*K) | Temperature (K) | Reference | Comment |
---|---|---|---|
44.780 | 299.81 | Gross, Oliver, et al., 1953 | T = 13 to 300 K. Unsmoothed experimental datum.; 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:
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
DRB - Donald R. Burgess, Jr.
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
DH - Eugene S. Domalski and Elizabeth D. Hearing
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
Tboil | 360.9 ± 0.7 | K | AVG | N/A | Average of 11 values; Individual data points |
Quantity | Value | Units | Method | Reference | Comment |
Tfus | 201. ± 6. | K | AVG | N/A | Average of 14 values; Individual data points |
Quantity | Value | Units | Method | Reference | Comment |
Ttriple | 203.68 | K | N/A | Gross, Oliver, et al., 1953, 2 | Crystal phase 1 phase; Uncertainty assigned by TRC = 0.05 K; by adiabatic calorimeter; TRC |
Ttriple | 203.670 | K | N/A | Huffman, 1948 | Crystal phase 1 phase; Uncertainty assigned by TRC = 0.02 K; TRC |
Ttriple | 203.670 | K | N/A | Huffman, 1947 | Crystal phase 1 phase; Uncertainty assigned by TRC = 0.03 K; TRC |
Ttriple | 203.670 | K | N/A | Huffman, 1947 | Crystal phase 1 phase; Uncertainty assigned by TRC = 0.02 K; TRC |
Quantity | Value | Units | Method | Reference | Comment |
ΔvapH° | 8.08 | kcal/mol | N/A | Reid, 1972 | AC |
ΔvapH° | 8.08 | kcal/mol | N/A | Johnson, Prosen, et al., 1949 | DRB |
Enthalpy of vaporization
ΔvapH (kcal/mol) | Temperature (K) | Method | Reference | Comment |
---|---|---|---|---|
8.13 | 299. | A | Stephenson and Malanowski, 1987 | Based on data from 284. to 363. K.; AC |
8.08 | 304. | N/A | Forziati, Norris, et al., 1949 | Based on data from 289. to 362. K.; AC |
Antoine Equation Parameters
log10(P) = A − (B / (T + C))
P = vapor pressure (atm)
T = temperature (K)
View plot Requires a JavaScript / HTML 5 canvas capable browser.
Temperature (K) | A | B | C | Reference | Comment |
---|---|---|---|---|---|
288.7 to 361.89 | 3.9490 | 1226.557 | -50.393 | Forziati, Norris, et al., 1949, 2 | Coefficents calculated by NIST from author's data. |
Enthalpy of fusion
ΔfusH (kcal/mol) | Temperature (K) | Reference | Comment |
---|---|---|---|
0.261 | 203.7 | Domalski and Hearing, 1996 | AC |
Entropy of fusion
ΔfusS (cal/mol*K) | Temperature (K) | Reference | Comment |
---|---|---|---|
10.56 | 146.8 | Domalski and Hearing, 1996 | CAL |
1.28 | 203.7 |
Enthalpy of phase transition
ΔHtrs (kcal/mol) | Temperature (K) | Initial Phase | Final Phase | Reference | Comment |
---|---|---|---|---|---|
1.5510 | 146.80 | crystaline, II | crystaline, I | Gross, Oliver, et al., 1953 | DH |
0.25779 | 203.68 | crystaline, I | liquid | Gross, Oliver, et al., 1953 | DH |
Entropy of phase transition
ΔStrs (cal/mol*K) | Temperature (K) | Initial Phase | Final Phase | Reference | Comment |
---|---|---|---|---|---|
10.57 | 146.80 | crystaline, II | crystaline, I | Gross, Oliver, et al., 1953 | DH |
1.27 | 203.68 | crystaline, I | liquid | Gross, Oliver, et al., 1953 | 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.
Johnson, Prosen, et al., 1949
Johnson, W.H.; Prosen, E.J.; Rossini, F.D.,
Heats of combustion and isomerization of the six C7H14 alkylcyclopentanes,
J. Res. NBS, 1949, 42, 251-255. [all data]
Gross, Oliver, et al., 1953
Gross, M.E.; Oliver, G.D.; Huffman, H.M.,
Low-temperature thermal data for some C7H14 alkylcyclopentanes,
J. Am. Chem. Soc., 1953, 75, 2801-2804. [all data]
Gross, Oliver, et al., 1953, 2
Gross, M.E.; Oliver, G.D.; Huffman, H.M.,
Low temperature thermal data for some C7H14 alkylcyclopentanes,
J. Am. Chem. Soc., 1953, 75, 2801. [all data]
Huffman, 1948
Huffman, H.M.,
Personal Commun., U. S. Bur. Mines, Bartlesville, OK, 1948. [all data]
Huffman, 1947
Huffman, H.M.,
Personal Communication, U. S. Bur. Mines, Bartlesville, OK, 1947. [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]
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]
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]
Forziati, Norris, et al., 1949, 2
Forziati, A.F.; Norris, W.R.; Rossini, F.D.,
Vapor Pressures and Boiling Points of Sixty API-NBS Hydrocarbons,
J. Res. Natl. Bur. Stand. (U.S.), 1949, 43, 6, 555-563, https://doi.org/10.6028/jres.043.050
. [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 S°liquid Entropy of liquid at standard conditions Tboil Boiling point Tfus Fusion (melting) point Ttriple Triple point temperature 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 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.