Cuprous equilibrium constant

Cuprous acetate monomer, complexed with the quinoline solvent, is in rapid equilibrium with dimer. The equilibrium constant is such that dimer formation is incomplete. Activation of the hydrogen occurs by a slow reaction between dimer complex and dissolved molecular hydrogen. Following activation of the hydrogen, the substrate quickly reacts with the hydrogen. Reaction (11) is believed rate controlling. Weller and Mills (5) attempted to establish whether the reaction went through a two-step oxidation and reduction of the Cu1 catalyst however, the conclusion was that the reaction depicted above best fits the observed facts. 

Copper ferrites have been included in the model, but have as yet not been found to be equilibrium controls on copper or iron solubility. The calculated activity products for the two minerals, cuprous ferrite and cupric ferrite, are characteristically several orders of magnitude oversaturated when compared to their respective equilibrium constants in a wide variety of surface waters. 

For TIOA with hydrochloric acid the concentration-based equilibrium constant for salt formation" according to reaction (8.2-6) is 1.51 x 10 and the equilibrium constant for amine-hydrochloride salt dimerization" is 8.0 M Combination of these parameters and the ion-complex stability constants with experimental metal-distribution data allows determination of the equilibrium constants for reactions (8.2-5) or (8.2-7). This completes the description of the amine-metal extraction-phase equilibria. For cobalt(II) in acidic sodium chloride solutions the equilibrium constant" for reaction (8.2-7) with TIOA is 2.0 X 10 and that for coppeifll) is 370 The corresponding value for zinc" is 7.5 x 10 Af -In spile of these relative values, the order of selectivity of TIOA for extraction of the metals is Zn > Cu > Co because of the relative extent of chloride complex formation. For the same reason, zinc stripping is difficult in this system, and copper has a tendency to be reduced to cuprous, which also complexes and extracts extensively. 

Most likely the earliest solution work reported was a study of linewidth measurements of the Cu resonance signal in concentrated hydrochloric acid solution containing cuprous and cupric chloride. These studies afforded reasonable calculations for the bimolecular rate constant for the equilibrium electron-exchange process (Eq. 1) ... 

In aqueous solution only low equilibrium concentrations of Cu+ (< 10 2M) can exist (see below) and the only cuprous compounds that are stable to water are the highly insoluble ones such as CuCl or CuCN. This instability towards water is due partly to the greater lattice and solvation energies and higher formation constants for complexes of the cupric ion, so that ionic Cu1 derivatives are unstable. 

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