Entropy, standard

Entropy. Standard entropies can be estimated by available methods (216—218). 

Standard entropy The total amount of energy in a given amount of substance at 298 K divided by the substances absolute temperature, also 298 K. Note carefully that an object may contain energy, but not entropy. Standard entropy is the description of how much energy has been dispersed into a substance in order for it to have a temperature of298 K. 

McCullogh, Scott et al. also give the values of thermodynamic functions such as entropy, standard heat, standard free energy etc., at temperatures from 0° to... 

The present section is fundamental in the sense that both the methodology for interrelating various thermodynamic functions of state introduced in Section 1.16 and the final results will be utilized over and over in subsequent portions of this book. It should be noted in passing that whenever thermodynamic relations involve the entropy, standard operating procedure calls for the immediate substitution for S in terms of measurable quantities. These matters are illustrated below. 

R. A. Alberty, Standard molar entropies, standard entropies of formation, and standard transformed entropies of formation in the thermodynamics of enzyme-catalyzed reactions, J. Chem. Thermodyn., in press. 

The following guidelines for absolute entropy (standard molar entropy) for individual substances can also be helpful in predicting entropy changes. 

Standard entropy Standard vapor Gibbs eneigy... 

Since G. N. Lewis avoided entropy in his early works, it seems appropriate to conclude with a couple of passages from the influential text that he co-authored with Merle Randall in 1923. Lewis and Randall took considerable care to explain entropy, devoting separate chapters to its numerical calculation (both thermodynamic and statistical mechanical), the third law understood entropically, and atomic entropies (standard molar entropy values), areas to which Lewis made important experimental contributions. And they wrote ... 

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