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S Molar entropy

G = Gibbs molar free energy S = molar entropy F = Helmholtz free molar energy H = molar enthalpy U = molar internal energy... [Pg.148]

Fig. 2.16 The molar entropy for nitrogen adsorbed ongraphitizedcarbon (Graphon) at — 189-3°C, as a function of the amount adsorbed s, = molar entropy of adsorbed nitrogen s, = molar entropy of liquid nitrogen. (Courtesy Hill, Emmett and Joyner.)... Fig. 2.16 The molar entropy for nitrogen adsorbed ongraphitizedcarbon (Graphon) at — 189-3°C, as a function of the amount adsorbed s, = molar entropy of adsorbed nitrogen s, = molar entropy of liquid nitrogen. (Courtesy Hill, Emmett and Joyner.)...
S Entropy, e.u./mole S Molar entropy of ideal gas e.u./mole... [Pg.114]

Power, radiant flux watt W J/s Molar entropy joule per mole-kelvin J/(mol K)... [Pg.1058]

To characterize the state of the adsorbed phase, it is useful to evaluate its molar entropy, s , defined as the mean molar value for all the molecules adsorbed over the complete range of surface coverage up to the given amount adsorbed. The molar integral entropy of adsorption. As, is then defined as... [Pg.13]

A Helmholtz energy J Btu S Molar or unit-mass entropy J/(mol-K) Btu/(lb mol-R)... [Pg.512]

The entropy of a substance, unlike its enthalpy, can be evaluated directly. The details of how this is done are beyond the level of this text, but Figure 17.4 shows the results for one substance, ammonia. From such a plot you can read off the standard molar entropy at 1 atm pressure and any given temperature, most often 25°C. This quantity is given the symbol S° and has the units of joules per mole per kelvin (J/mol-K). From Figure 17.4, it appears that... [Pg.455]

The third law of thermodynamics establishes a starting point for entropies. At 0 K, any pure perfect crystal is completely constrained and has S = 0 J / K. At any higher temperature, the substance has a positive entropy that depends on the conditions. The molar entropies of many pure substances have been measured at standard thermodynamic conditions, P ° = 1 bar. The same thermodynamic tables that list standard enthalpies of formation usually also list standard molar entropies, designated S °, fbr T — 298 K. Table 14-2 lists representative values of S to give you an idea of the magnitudes of absolute entropies. Appendix D contains a more extensive list. [Pg.991]

Table 14-2 Standard Molar Entropies (S°) of Selected Substances at 298 K... Table 14-2 Standard Molar Entropies (S°) of Selected Substances at 298 K...
Equation refers to molar quantities. To obtain the total entropy of a sample, we must multiply its molar entropy by n, the number of moles. Example illustrates the calculation of A S for a change in concentration. [Pg.998]

A i reaction (CaO) + S (C02) - S (CaCO ) The entropy of each solid is its standard entropy, S °, but the entropy of the gas must be corrected for the deviation of pressure from standard conditions. Equation gives the molar entropy of carbon dioxide as a ftmction of its partial pressure S (CO2) — S ° (CO2) - i In p(pc02) Now substitute the corrected entropy of CO2 into the equation for A ... [Pg.1007]

C14-0135. S ° of graphite is 3 times larger than S ° of diamond. Explain why this is so. (You may need to review the structures and properties of graphite and diamond in Section 11-.) Buckminsterfullerene is a solid that consists of individual molecules with formula Cgo. Is the molar entropy of buckminsterfullerene larger or smaller than that of graphite How about the entropy per gram Explain. [Pg.1044]

The relative partial molar enthalpy, AHa, and the relative partial molar entropy, A,S a, are defined as... [Pg.277]

If a2/ax = gim2lgxmx m2/mx (a = activity, g = molal activity coefficient, m = molality) if Henry s law is obeyed and a = gm, mh and m2 are the molal solubilities of the polymorphs, and if the standard molar enthalpies and standard molar entropies of solution are, respectively,... [Pg.605]

P is pressure T is temperature V is the molar volume S is molar entropy... [Pg.701]

This property is described by the statement that entropy is a homogeneous first-order function of the extensive parameters. The expression is readily interpreted to define molar entropy (s = S/N), internal energy (it) and... [Pg.411]

The excess molar entropy of mixing is the real entropy of mixing minus the ideal entropy of mixing. Using a binary A-B solution as an example, Ae xSm s... [Pg.66]

Here A vac. S and A vacH are the molar entropy and enthalpy of formation of the defects. Using a pure metal like aluminium as an example, the fractional number of defects, heat capacity and enthalpy due to defect formation close to the fusion temperature are 5-10-4, 0.3 J K-1 mol-1 and 30 J mol-1 [30],... [Pg.260]

Restatement What is the standard molar entropy of HCOOH(s) ... [Pg.392]

In much the same fashion as the AH° was tabulated, the standard molar entropies (S°) of elements and compounds are tabulated. This is the entropy associated with 1 mol of a substance in its standard state. Unlike the enthalpies, the entropies of elements are not zero. For a reaction, it is possible to calculate the standard entropy change in the same fashion as the enthalpies of reaction ... [Pg.253]

Recently, the Pitzer equation has been applied to model weak electrolyte systems by Beutier and Renon ( ) and Edwards, et al. (10). Beutier and Renon used a simplified Pitzer equation for the ion-ion interaction contribution, applied Debye-McAulay s electrostatic theory (Harned and Owen, (14)) for the ion-molecule interaction contribution, and adoptee) Margules type terms for molecule-molecule interactions between the same molecular solutes. Edwards, et al. applied the Pitzer equation directly, without defining any new terms, for all interactions (ion-ion, ion-molecule, and molecule-molecule) while neglecting all ternary parameters. Bromley s (1) ideas on additivity of interaction parameters of individual ions and correlation between individual ion and partial molar entropy of ions at infinite dilution were adopted in both studies. In addition, they both neglected contributions from interactions among ions of the same sign. [Pg.64]


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See also in sourсe #XX -- [ Pg.5 ]




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