Estimation of the Heat Capacities of Organic Liquids as a Function of Temperature using Group Additivity. II. Compounds of Carbon, Hydrogen, Halogens, Nitrogen, Oxygen, and Sulfur

1993 ◽  
Vol 22 (3) ◽  
pp. 619-657 ◽  
Author(s):  
Vlastimil Růžička ◽  
Eugene S. Domalski
Keyword(s):  
Heat Capacities ◽  
Organic Liquids ◽  
Group Additivity

Additivity methods for estimating heat capacities of vaporization for organic compounds

1984 ◽  
Vol 62 (2) ◽  
pp. 361-372 ◽  
Author(s):  
J. Peter Guthrie ◽  
Kathleen F. Taylor
Keyword(s):  
Standard Deviation ◽  
Level Scheme ◽  
Correlation Matrix ◽  
Heat Capacities ◽  
Organic Liquids ◽  
Group Additivity ◽  
Group Level ◽  
Average Value ◽  
Atom Level ◽  
Atom Bond

Additivity methods permitting the estimation of heat capacities of vaporization for organic liquids have been developed, using atom, bond, and group additivity parameters. Previously it had been common to use an average value for all organic liquids, which can lead to considerable errors. For the atom level scheme, 193 compounds could be fitted using 20 parameters, with a standard deviation of 1.50 cal/deg/mol, and only 29 deviations greater than 2 cal/deg/mol. For the bond level scheme, 197 compounds could be fitted using 23 parameters, with a standard deviation of 1.47 cal/deg/mol, and only 37 deviations greater than 2 cal/deg/mol. For the group level scheme, 177 compounds could be fitted using 39 parameters, with a standard deviation of 1.05 cal/deg/mol, and only 13 deviations greater than 2 cal/deg/mol. The significant terms in the correlation matrix are given for each set of parameters.

A group additivity approach for the estimation of heat capacities of organic liquids and solids at 298 K

1993 ◽  
Vol 4 (4) ◽  
pp. 261-269 ◽  
Author(s):  
James S. Chickos ◽  
Donald G. Hesse ◽  
Joel F. Liebman
Keyword(s):  
Heat Capacities ◽  
Organic Liquids ◽  
Group Additivity

Heat capacities at constant volume, free volumes, and rotational freedom in some liquids

1971 ◽  
Vol 24 (9) ◽  
pp. 1817 ◽  
Author(s):  
DD Deshpande ◽  
LG Bhatgadde
Keyword(s):  
Heat Capacity ◽  
Free Volume ◽  
Heat Capacities ◽  
Organic Liquids ◽  
Velocity Of Sound ◽  
Velocity Data ◽  
Volume Analysis ◽  
Straight Lines ◽  
Rotational Freedom ◽  
Residual Heat

This paper presents the experimental results on the velocity of sound, densities, and heat capacities of eight organic liquids at 25�, 35�, and 45�C. Using Eyring's equation, the free volumes have been calculated from the sound velocity data. For pure liquids, a quantity Cv* = (Cv)L- (Cv)g- Cstr called the residual heat capacity is found to be linearly dependent on free volume. Analysis of the data for 34 liquids shows that a plot of residual heat capacity against the free volume gives a series of straight lines differing in slopes for different groups of liquids such as hydrocarbons, halogen-substituted hydrocarbons, alcohols, etc. This behaviour is ascribed as being due to different degrees of rotational freedom of molecules in these liquids.

Molar heat capacities of alkanolamines from 299.1 to 397.8 K Group additivity and molecular connectivity analyses

1997 ◽  
Vol 93 (9) ◽  
pp. 1747-1750 ◽  
Author(s):  
Yadollah Maham ◽  
Loren G. Hepler ◽  
Alan E. Mather ◽  
Andrew W. Hakin ◽  
Robert A. Marriott
Keyword(s):  
Heat Capacities ◽  
Group Additivity ◽  
Molecular Connectivity

Heats of vaporization and gaseous heats of formation of some five- and six-membered ring alkenes

1979 ◽  
Vol 57 (17) ◽  
pp. 2302-2304 ◽  
Author(s):  
Richard Fuchs ◽  
L. Alan Peacock
Keyword(s):  
Gas Chromatography ◽  
Double Bond ◽  
Heat Capacities ◽  
Membered Ring ◽  
Heats Of Formation ◽  
Group Additivity ◽  
Liquid Heat ◽  
Heats Of Vaporization

The heats of vaporization of 1-methylcyclopentene, 3-methylcyclopentene, ethylidenecyclopentane, 1-ethylcyclopentene, methylenecyclohexane, allylcyclopentane, vinylcyclohexane, ethylidenecyclohexane, allylcyclohexane, 3,3-diethylpentane, 2,2,4,4-tetramethylpentane, and trans-2,2,5,5-tetramethyl-3-hexene have been measured by the gas chromatography – calorimetry method. These values have been combined with previously reported liquid heats of formation to give gaseous values of ΔHf. The results indicate that the internal double bond is favored by about 0.5 kcal over the exo in both 5- and 6-membered rings, but the endo–exo differences are much smaller than previously believed. Several of the liquid heat capacities that were measured were not well predicted by group additivity schemes.

Sign in / Sign up

Export Citation Format

Share Document