Standard Heats Of Formation Table

These gases take lower thermal stabilities than hydrogen sulphide equally expected from their enthalpies of formation Table ten.ii) and they are consequently more than powerful reducing agents than hydrogen sulphide. [Pg.284]

The methods summarized by Eqs. 8 and nine take both been applied to halocarbenes. The proton affinities obtained by ICR bracketing125 (Tabular array half dozen) are consistently lower than those derived from enthalpies of formation (Table 7). The instance of dichlorocarbene, with a difference in AH of fifteen kcal/mol), is peculiarly disturbing and has been analysed in some detail.134 Notably, the PA of CCl2 from an before bracketing experiment126 was closer to the enthalpy-derived PA. The discrepant results from like experiments125126 indicate that HCClJ is not a good substrate for proton transfer studies. [Pg.38]

Enthalpy of Formation. Tables of enthalpies of reaction mostly list the enthalpies of formation of various compounds in their standard states from the elements in their standard states at the specified temperature. Thus, if the standard tooth enthalpy of formation, Af//, of CO2 at 25°C is given as —393.509 kJ mol , the following equation is unsaid ... [Pg.48]

Consulting the standard enthalpies of formation (Table l4-iii), what is the enthalpy alter, AH, for this reaction ... [Pg.153]

Flowing ammonia has been applied to the synthesis of the nitrides of fe, cobalt, and nickel compounds with very low enthalpies of formation (Tabular array two). Again, isothermal atmospheric condition were employed. Ammonia is preferable over the use of molecular nitrogen to nitride... [Pg.97]

The enthalpy alter for this reaction can exist called the enthalpy of germination of water, A//y (H20). Table xiv.6 shows standard enthalpies of germination. Table 14.7 is a separate table for unbranched hydrocarbons. [Pg.404]

Trends in enthalpies of formation (Table 4) are not as regular as those of lattice energy. For fluorides, lattice energies dominate A//f therefore the smallest cation gives the nearly stable fluoride. For the other hahdes, the ease of production... [Pg.66]

If we compare the estimated enthalpies of formation (Table 1) for (Z,Z)-mucon-aldehyde (14a) and rroRj-cyclobutene-50,ii-dicarboxaldehyde (run across Eq. 4), we discover that the isomerization to 22b is endothermic by xvi.9 kcal/mol, most xi kcal/mol more endothermic than isomerization to the 2f/-pyran 19. This plausibly explains the rapid Z,Z to Z,Eastward isomerization coupled with very ho-hum Z, to , isomerization in the absence of nucleophiles. Thus, the first step could be unimolecular thermal rearrangement, while the second step under metabolic conditions could be the reversible Michael addition-isomerization. Of course, both steps could result from attack by nucleophiles either in the medium or on biological macromolecules. [Pg.327]

The synthesis and properties of several high-nitrogen materials with 3-amino-vi-nitroamino-tetrazine (ANAT) as the anion are reported (Scheme 23). These salts (99, 100, 103a,b) provide a new and piece of cake approach to highly energetic salts. All these salts are relatively dumbo (> 1.55 chiliad/cm ) and exhibit good thermal stability T > 148 C). The calculated detonation velocities and detonation pressures are comparable to those of explosives such as Tetryl, PETN, TATB, and RDX. A combination of theoretical and empirical calculations shows that all these salts accept high molar enthalpies of formation (Tabular array 9) [99]. [Pg.67]

Calculate the rut of vaporization, A.H°ap, of water, using standard enthalpies of formation (Tabular array 6.ii). [Pg.250]

Table B-ane SI Measurement Table B-2 Unit of measurement Symbols Table B-3 Symbols Tabular array B-4 Physical Constants Tabular array B-5 Enthalpy of Combustion Table B-half dozen The Elements Symbols, Atomic Numbers, and Atomic Masses Tabular array B-seven Common Ions Table B-eight Water-Vapor Force per unit area Table B-9 Densities of Gases at STP Table B-ten Density of Water Table B-xi Solubilities of Gases in Water Table B-12 Solubility Chart Table B-thirteen Solubility of Compounds Tabular array B-fourteen Enthalpy of Formation Tabular array B-15 Properties of Mutual Elements...

Table B-1 SI Measurement Table B-2 Unit of measurement Symbols Table B-3 Symbols Table B-4 Concrete Constants Tabular array B-5 Enthalpy of Combustion Tabular array B-half dozen The Elements Symbols, Atomic Numbers, and Diminutive Masses Table B-7 Common Ions Table B-8 H2o-Vapor Pressure Table B-9 Densities of Gases at STP Table B-x Density of Water Table B-11 Solubilities of Gases in H2o Table B-12 Solubility Chart Table B-13 Solubility of Compounds Table B-14 Enthalpy of Formation Table B-15 Properties of Common Elements...

Standard Enthalpies of Formation—By arbitrarily assigning an enthalpy of zero to the reference forms of the elements in their standard states, the enthalpy alter in the formation of a compound from its elements becomes a standard enthalpy of germination (AfH°). Using tabulated standard enthalpies of germination (Table vii.2), information technology is possible to calculate standard enthalpies of reactions without having to perform additional experiments (equation seven.22). [Pg.288]

Table v.1 gives a sample adding of the NHVj for toluene, starting from the molar enthalpies of formation of the reactants and products and the enthalpies of changes in state as the case requires. [Pg.181]

The enthalpy (strictly, the enthalpy change) for a reaction tin readily be calculated from enthalpies of formation AHf which can often be obtained from tables of data. [Pg.63]

Information on proton affiri itics (gas ph asc) of m any differen t com poti u ds (see Tabular array 2) deni on strate Lh due east h igh level of accurateness possible in determ in in g energies of related species. In th is written report by Dew-ar and Dieter , the enthalpy of formation of II is the experimental value (367.two kcal/moll. The calculated value for H is unreliable. [Pg.132]

Arylthiazoles derivatives are skillful subjects for the study of these transfers. Thus the absorption wavelengths and the enthalpies of formation of a series of accuse-transfer complexes of the blazon arylthiazole-TCNE, have been adamant (147). The results are given in Table IIM3. [Pg.354]

This table gives the first ionization potential in MJ mol and in electron volts. Also listed is the enthalpy of formation of the ion at 25°C (298 Yard). [Pg.283]

Several portions of Section 4, Properties of Atoms, Radicals, and Bonds, take been significantly enlarged. For case, the entries under Ionization Free energy of Molecular and Radical Species now number 740 and have an additional cavalcade with the enthalpy of germination of the ions. Likewise, the table on Electron Affinities of the Elements, Molecules, and Radicals at present contains about 225 entries. The Table of Nuclides has textile on boosted radionuclides, their radiation, and the neutron capture cantankerous sections. [Pg.1283]

Physical properties of the acid and its anhydride are summarized in Table i. Other references for more data on specific physical properties of succinic acid are as follows solubiUty in h2o at 278.fifteen—338.15 M (12) water-enhanced solubiUty in organic solvents (13) dissociation constants in water—acetone (10 vol %) at 30—60°C (14), water—methanol mixtures (10—50 vol %) at 25°C (15,16), water—dioxane mixtures (10—50 vol %) at 25°C (15), and water—dioxane—methanol mixtures at 25°C (17) nucleation and crystal growth (eighteen—20) calculation of the enthalpy of formation using semiempitical methods (21) enthalpy of solution (22,23) and enthalpy of dilution (23). For succinic anhydride, the enthalpies of combustion and sublimation have been reported (24). [Pg.534]

Values for the free free energy and enthalpy of formation, entropy, and ideal gas heat capacity of carbon monoxide as a function of temperature are listed in Table ii (1). Thermodynamic properties have been reported from 70—300 Thousand at pressures from 0.1—thirty MPa (1—300 atm) (eight,9) and from 0.1—120 MPa (one—1200 atm) (10). [Pg.48]

Table 1.5. Standard Enthalpies of Formation of Some Hydrocarbons (kcal/mol) ...

Tabular array 1.5. Standard Enthalpies of Germination of Some Hydrocarbons (kcal/mol) ...

Theoretical studies of the relative stabilities of tautomers 14a and 14b were carried out mostly at the semiempirical level. AMI and PM3 calculations [98JST(T)249] of the relative stabilities carried out for a series of iv(5)-substituted imidazoles xiv (R = H, R = H, CH3, OH, F, NO2, Ph) are mostly in accord with the determination based on the Charton s equation. From the comparing of the electronic spectra of 4(5)-phenylimidazole fourteen (R2 = Ph, R = R3 = H) and two,4(5)-diphenylimidazole fourteen (R = R = Ph, R = H) in ethanol with those calculated past using ir-electron PPP method for each of the tautomeric forms, it follows that calculations for type 14a tautomers match the experimentally observed spectra better (86ZC378). The AMI calculations [92JCS(P1)2779] of enthalpies of formation of 4(5)-aminoimidazole fourteen (R = NH2, R = R = H) and 4(five)-nitroimidazole 14 (R = NO2, R = R = H) point to tautomers 14a and 14b respectively equally being energetically preferred in the gas phase. Both predictions are in disagreement with expectations based on Charton s equation and the data related to basicity measurements (Tabular array III). These inconsistencies may be... [Pg.178]

Table ii Calculated and experimental values for the equilibrium volumes, bulk moduli and enthalpies of formation.

Table 2 Calculated and experimental values for the equilibrium volumes, majority moduli and enthalpies of formation.

Tabular array two gives our calculated results for the equilibrium volume Vq, bulk modulus Bq, and enthalpy of formation AH. Theoretical results refer to T=0, uncorrected for naught point motility, whereas experimental values refer to room temperature. Annotation that the extensive quantities AH and Vq arc reported per atom in the present paper, i.e., divided by the total number of atoms. Besides known the LDA underestimates the volume. Comparing the majority modulus for T3 and D8s we see that the addition of Si to pure Ti has a large (26 %) effect on the bulk modulus, indicating that p electrons of Si have a stiff effect on the bonding in this system. [Pg.193]

Enthalpies of formation for a variety of compounds are listed in Table 8.three. Notice that, with a few exceptions, enthalpies of formation are negative quantities. This ways that the germination of a compound from the elements is normally exothermic. Conversely, when a compound decomposes to the elements, heat unremarkably must be captivated. [Pg.208]

You volition annotation from Table 8.iii that at that place are no entries for elemental species such as Br2(l) and O2(g). This is a effect of the manner in which enthalpies of formation are divers. In upshot, the enthalpy of formation of an element in its stable state at 25°C and one atm is taken to be zero. That is,... [Pg.208]

The standard enthalpies of germination of ions in aqueous solution listed at the bottom of Table 8.3 are relative values, established past taking... [Pg.209]

Strictly speaking, AH° calculated from enthalpies of formation listed in Table 8.3 represents the enthalpy change at 25°C and 1 atm. Actually, AH is contained of force per unit area and varies relatively piffling with temperature, changing past peradventure i to 10 kj per 100°C. [Pg.210]

Table 4.3 summarizes values taken from the JANAF tables for the Gibbs free energy functions and standard enthalpies of germination for a few common substances. The JANAF tables provide a more than complete tabulation. [Pg.193]

We will run across in a later chapter how to calculate A,H° from enthalpies of formation, from which ArG° tin exist calculated using Table 4.3 and equations (iv.34) or (4.36). [Pg.193]

Extensive tabulations of standard enthalpies of formation and related thermodynamic data can be found in the literature.5 Table nine.1 summarizes selected values from these sources. [Pg.453]

Table 9.1 Standard heat capacities, entropies, enthalpies of germination, and Gibbs free energies of germination at T = 298.xv K. ...

Table nine.i Standard rut capacities, entropies, enthalpies of formation, and Gibbs gratuitous energies of germination at T = 298.xv K. ...

The group contributions are given in Table half dozen. The grouping values were used to predict the enthalpy of formation of every compound in Tables i-five (except for those containing nitrogen). The estimated values were and then compared to the experimental values. The agreement was normally to inside about 10 kJ mol f The worst cases were for butyl methyl sulfone, t-butyl methyl sulfone and 50-methyl-iv-(l-methylethenylsulfonyl)benzene, for which the deviations were 12.4, 14.0 and 12.three kJ mol-one, respectively. The average deviation was 4.4kJ mol-1. [Pg.100]