Copper thermodynamic data

Exactly the same problem arises with the recent studies of NiO solubility by Tremaine and Leblanc (25) and again the thermodynamic data on the aqueous anionic species at 300 C are likely to be more reliable than on the Ni + ion. There is good spectroscopic evidence for complex formation in chlorides of nickel (II), (26) cobalt (II) (27), and copper (II) (28) at 300°C and above. Most of the work was done at rather high Cl concentrations but qualitatively the effects of dielectric constant and concentration are as expected. A noteworthy feature (which estimation procedures will have to allow for) is the change from 6 to 4 coordination at the lower pressures (150-300 bar) and the higher Cl concentrations. This change appears to take place with only 2 or 3 Cl ions coordinated to the metal (at least in the case of Ni(II)). 

Copper chelates with diamines dissociate about 200-400 times moie rapidly than the corresponding nickel complex. If the same situation pertains with the monoammonia complex, an estimated dissociation rate constant, with thermodynamic data, yields the value shown. 

Crystal field theory is one of several chemical bonding models and one that is applicable solely to the transition metal and lanthanide elements. The theory, which utilizes thermodynamic data obtained from absorption bands in the visible and near-infrared regions of the electromagnetic spectrum, has met with widespread applications and successful interpretations of diverse physical and chemical properties of elements of the first transition series. These elements comprise scandium, titanium, vanadium, chromium, manganese, iron, cobalt, nickel and copper. The position of the first transition series in the periodic table is shown in fig. 1.1. Transition elements constitute almost forty weight per cent, or eighteen atom per cent, of the Earth (Appendix 1) and occur in most minerals in the Crust, Mantle and Core. As a result, there are many aspects of transition metal geochemistry that are amenable to interpretation by crystal field theory. 

It is relatively simple to remember that the solubility product is the product of the soluble species.) For the solid precipitate to form, the product of the copper ion concentration and the hydroxide ion concentration squared must exceed the numerical value of Ksp. Thermodynamic data can provide the needed values of the free energies of the ionic species. Then the value of Ksp can be determined directly (the Ksp for Cu(0H)2 is 1.58 x 10 ). Keep in mind that the equilibrium hydroxide ion concentration is defined by the pH of the water solution. So for any metal ion concentration, we can predict the maximum pH before the precipitate will be formed. 

AG° = 31.9 kJmol-1 for reaction 32. This value should be compared to the thermodynamic redox potentials for the process with 1 M 02 as the standard state. The relevant redox potentials are 0.158 and —0.16 V for the reduction of Cu(II) and 02 (Sawyer and Valentine, 1981), respectively. From these thermodynamic data we calculate AG° = — nFE° = 30.1 kJmol-1. The close agreement indicates that the redox kinetics of copper in natural waters is, indeed, governed by reaction 32 as the rate-limiting step. 

Recently a convenient and precise method has been devised for the determination of thermodynamic data for copper (I)-olefin complexes 67> based on the coulometric generation of Cu(I) and potentiometric measurement of the Cu(I) activity in a lithium perchlorate-2-propanol medium. The formation constants for the reaction Cu(I) (2-propanol) + olefin (2-propanol) Cu(I) olefin (2-propanol), were found to be linearly related to those of the corresponding... 

Table 9. Thermodynamic data for copper(I) cycloolefin complex formation at 30 °C in 1M Li CIO4...

LAR/CER] Larson, J. W., Cerutti, P., Garber, H. K., Hepler, L. G., Electrode potentials and thermodynamic data for aqueous ions. Copper, zinc, cadmium, iron, cobalt, and nickel, J. Phys. Chem., 72, (1968), 2902-2907. Cited on pages 84, 332. 

Thermodynamic data have been reported for the formation of copper(n)... 

For iron, nickel, and chromium the experimental values of passivation and the thermodynamic data in the Pourbaix diagram are quite different because additional kinetic effects determine the regions of passivity and active dissolution for these metals. For other metals, e.g., zinc and copper the correspondence between the Pourbaix diagram and regions of stability and corrosion is better. 

O.J. Kleppa, Approximate Thermodynamic Data from the Systems Copper-bismuth, Copper-lead and Copper-thallium , J.Am.Chem.Soc.. Vol. 74,1952,6047-6051. 

Gergely and Kiss [Ge 77] performed a calorimetric investigation of the thermodynamic data of the formation of copper(II) complexes of alanine, phenylalanine and tyrosine in water-dioxane solvent mixtures. In connection with the protonation constants of the ligands, they showed that a change in the solvent... 

We have shown that pyrrole can be electropolymerized on various oxidizable metals such as iron, mild steel, aluminum, copper, tin and zinc, and that this can be achieved in one or two steps. During our investigations, the strategy adopted was to circumvent the unfavorable thermodynamic data by the optimization of kinetic conditions. To this end, we have developed various processes, in which the metal is initially passivated with respect to corrosion... 

Based on thermodynamic data, the partial pressure of sulphur dioxide in the roaster bed and the bed gas temperature range have been selected to maximize production of soluble copper and cobalt and minimize production of soluble iron. 

Figure 20. Predicted speciation of copper(II) in a 0.1 m Cu solution based on current thermodynamic data (Wagman etal. 1982).

Figure 23. Stability field of copper(I) as CuCls" predicted from thermodynamic data in Wagman etal. (1982).

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