Uses of Thermodynamic Data

Values for many thermodynamic quantities are essential for use in chemical engineering for the design of plant. Thus, for example, a knowledge of enthalpy changes is necessary for the design of heaters, coolers, and condensers and for the removal or supply of heat to chemical reactors. 

In industry, a position is now being approached where very large plant can be erected using basic data on the properties of the starting materials and products. For example, Lord Shackleton has summarized the situa- 

8S90 Dasent, Non-existent Compounds. Compounds of Low Stability , Edward Arnold and M. Dekker, London and New York, 1965. 

Lord Shackleton, Speech on the European Technological Community, 25 April, 1968 Ministry of Technology press notice, 26 April, 1968. 

The practical importance of thermodynamic theory lies in the fact that, given certain basic data, its principles permit the exact calculation of other data and the state of equilibrium of systems under specified conditions. Thus thermodynamic theory will allow one to state the feasibility of a hypothetical reaction and the maximum yield of a desired product which is to be expected. Use of approximate expressions for this latter purpose may sometimes be justified. For example, the defining equation for standard Gibbs energy change at temperature Tis the expression  

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D. R. Stull, E. F. Westrum, Jr., and G. C. Sinke, The Chemical Thermodynamics of Organic Compounds, John Wiley and Sons, Inc., New York, 1969. Summarizes AH° of formation of some 4500 organic compounds and AG° values for about half that many. Includes many valuable descriptions of the use of thermodynamic data in the planning of industrial processes. 

When writing equations, two sets of possible products may look reasonable until the reaction is considered from the point of view of the thermodynamic changes involved. In many cases, the use of thermodynamic data allows the correct products to be identified. The predictive power of thermodynamics in deciding how reactions take place should not be overlooked. 

When biomass is combusted under normal conditions, a flame is produced as visible radiation, provided oxidation occurs at a sufficient rate. By use of thermodynamic data, the theoretical temperature at which the products of combustion form under adiabatic, reversible conditions can be calculated. The theoretical flame temperature for the combustion of wood of various moisture... 

Standard State and Reference State Equation 53 contains two quantities which require precise definition in order to make use of thermodynamic data or render experimental observation into the framework of the equation. We need to specify the condition of a mixture for which 7, 1. This is the... 

The use of thermodynamic data for predicting the reaction path can, for example, be applied for the thermal decomposition of aliphatic hydrocarbons. This example is more related to practical applications for petroleum products, but can explain the yield of certain compounds in secondary steps for the pyrolysis of polymers such as rubber. 

One of the most important uses of thermodynamic data is the evaluation of the feasibility of proposed chemical reactions, which have perhaps never been studied in the laboratory. Let us imagine, for example, that the reaction of NO3 with H2O might be an important source of HNO3 ... 

Another important use of thermodynamic data in atmospheric applications is the evaluation of the exothermicity of chemical reactions which may play a role in the thermal budget of the atmosphere. Consider, for example, the addition of atomic oxygen to molecular oxygen ... 

The effects of pH and Cl ion concentration on the species distribution of platinum compounds have been used to fashion the following plausible argument for the chemistry of cw-DDP in vivo. With the use of thermodynamic data for the ethylenediamine (en) analogue [Pt(en)Cl2], the relative concentrations of hydrolyzed species at pH 7.4 were estimated (see Table 9.3) for blood plasma and cytoplasm (Figure 9.7). The higher chloride ion concentration in... 

The VTE and the Adam-Gibbs equations are useful because they permit the use of thermodynamic data, obtained by calorimetric methods, to describe molecular motions in undercooled liquids and glasses. Most investigations of pharmaceutical solids rely on calorimetric measurements, and for that reason their discussion is deferred until the fundamentals of the methods have been described in the following section. 

Cha] Chart, T.G., Coimsell, J.F., Jones, G.P, Slough, W., Spencer, P.J., Provision and Use of Thermodynamic Data for the Solution of High-Temperature Practical Problems , Int. Met. Rev., 20, 57-82 (1975) (Assessment, Phase Diagram, Phase Relations, Review, 212)... 

This should point out how crucial it is to be consistent in the use of thermodynamic data and tabulated activity coefficient values. 

In this last work are present many interesting intuitions, there is an hypothesis of the microscopic interaction mechanism and from that and the stoichiometric coefficients a tiy to explain theoretically the exponential coefficients, previously arbitrary or purely phenomenological and there is a rruld use of thermodynamic data. 

There is still an even more basic limitation to the usefulness of thermodynamic data for making predictions about reactions Thermodynamic data can provide no information about the energy requirements of the pathways that the potential... 

Practical Prediction of Phase Stability 2.1. Metals Use of Thermodynamic Data... 

Lee, J.H. Lee, D.N. Use of thermodynamic data to calculate surface tension and viscosity of Sn-based soldering alloy systems. J. Electron. Mater. 2001, 30 (9), 1112-1119. 

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