Concentration Diagrams

Figure 1 gives an enthalpy-concentration diagram for ethanol(1)-water(2) at 1 atm. (The reference enthalpy is defined as that of the pure liquid at 0°C and 1 atm.) In this case both components are condensables. The liquid-phase enthalpy of mixing... 

Figure 5-1. Enthalpy concentration diagram for ethanol-water at 1.013 bar.

Enthalpy-Concentration Diagram for Aqueous Sulfuric Acid... 

FIG. 2-10 Enthalpy-concentration diagram for aqueous ethyl alcohol. Reference states Enthalpies of hquid water and ethyl alcohol at 0 C are zero. NOTE In order to interpolate equilihrium compositions, a vertical may he erected from any liquid composition on the hoihug hue and its intersection with the auxihary hue determined. A horizontal from this intersection will estahhsh the equihhrium vapor composition on the dew hue. (Bosnjakovic, Techuische Thermo-dynamik, T. Steinkopff, Leipzig, 1935. )... 

FIG. 2-11 Enthalpy-concentration diagram for aqueous hydrogen chloride at 1 atm. Reference states enthalpy of liquid water at 0 C is zero enthalpy of pure saturated HCl vapor at 1 atm (—85.03 C) is 8000 kcal/moL NOTE It should he observed that the weight basis includes the vapor, which is particularly important in the two-phase region. Saturation values may be read at the ends of the tie lines. [Van Nuys, Trans. Am. Inst. Chem. Eng., 39, 663 (1943).]... 

FIG. 11-100 Temperahire -pressure-concentration diagram of saturated LiBr-water solutions (Vl- K Stoecke7 and J. Jones Refrigeration and. Conditioning)... 

Free-energy-concentration diagrams have been used in the study of the thermodynamic influence on the non-stoichiometry of the solid titanium carbide deposited from H2-CH4-TiCl4 gas mixtures at 1 900 K. The authors show how, from the partial pressure measurements of Ti vapour over a range of... 

Concentration Diagrams and the Effect of Physicai and Chemicai Factors on the Composition and Stabiiity of Surface interaction Layers (Fe, -Zn, . 

Figure 7.87 shows a AG -concentration diagram for Fe(j,-Zn( ). It was constructed from the experimental data shown in Table 7.37. The method of construction is described elsewhere. Figure 7.87 can now be used, by applying the constraints imposed by the tangency rule, to explain why in Fig. 7.88a and b, where the chemical potentials (shown in the diagram) of zinc vapour varied between 0 and - 1 - 81 kJ molthe total interaction surface layer consisted of T, T, 6, and flayers in Fig. 7.88c at a chemical potential only slightly lower ( — 2-11 kJmol ) only T and T, layers were present whilst at -2-55 kJ mol only a F outermost layer was formed. 

The micrographs in Fig. 7.88 show clearly how from a knowledge of the AG -concentration diagrams it is possible to select the exact reaction conditions for the production of tailor-made outermost surface phase layers of the most desired composition and thus of the optimum physical and chemical properties for a given system. In addition it shows that according to thermodynamics, there can be predictable differences in the composition of the same outermost phase layer prepared at the same conditions of temperature but under slightly different vapour pressures. 

Previous studies clearly indicated that the chemical compositions of geothermal waters are intimately related both to the hydrothermal alteration mineral assemblages of country rocks and to temperature. Shikazono (1976, 1978a) used a logarithmie cation-Cl concentration diagram to interpret the concentrations of alkali and alkaline earth elements and pH of geothermal waters based on thermochemical equilibrium between hydrothermal solution and alteration minerals. 

Enthalpy-concentration diagrams greatly facilitate the calculation of energy balances involving concentration and phase changes this is illustrated in Example 3.6. 

The maximum temperature will occur if there are no heat losses (adiabatic process). As no heat or material is removed, the problem can be solved graphically in the enthalpy-concentration diagram (Figure 3.3). The mixing operation is represented on the diagram... 

Figure 3.3. Enthalpy-concentration diagram for aqueous ammonia. Reference states enthalpies of liquid water at 0°C and liquid ammonia at —77°C are zero. (Bosniakovic, Technische Thermodynamik, T. Steinkopff,... 

Himmelbau (1995) or any of the general texts on material and energy balances listed at the end of Chapter 2. The Ponchon-Savarit graphical method used in the design of distillation columns, described in Volume 2, Chapter 11, is a further example of the application of the lever rule, and the use of enthalpy-concentration diagrams. 

The heat of dilution was calculated from an enthalpy — concentration diagram given in Perry s Chemical Engineers Handbook, 5th edn, p. 3.205, Figure 3.42. 

Taking the datum as 0°C for this calculation, so the enthalpy-concentration diagram can be used directly. 

From enthalpy-concentration diagram, enthalpy of mixed acid... 

Fig. 38. Temperature concentration diagram for polymer solutions [102,103]. x = (T — )/0 ( -temperature, c monomer concentration (see Table 5)...

Figure 4. The temperature-electrolyte concentration diagram, defining regions of different anodic dissolution phenomena, according to Fukushima et al9...

Vincente-Perez, S. Durand, J. S. Alvarez, M. D. 1992. Limitations of complexes logarithmic diagrams as a function of the ligand concentration-diagrams of conditioned variable. An. Quim. 88(7-8) 683-688. 

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