ISSN:
1572-8927
Keywords:
Thermodynamic transfer quantities
;
acetonitrile
;
pyridine
;
2-hydroxycyanoethane
;
aqueous organic solvent mixtures
;
Cu2+, Cu+, and Ag+ ions
;
hydrometallurgy
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Abstract Free energies and Walden products show that the Cu+ and Ag+ ions are specifically solvated by acetonitrile (AN), 2-hydroxycyanoethane (HAN), and by pyridine (Py) whereas Na+ is specifically solvated by water, in mixtures of these organics with water. The Cu2+ ion is specifically solvated by pyridine in pyridine-water mixtures, but by water in acetonitrile-water mixtures. Ion-solvent, coordinated solvent-bulk solvent, and solvent-solvent interactions produce large entropy losses in the order Cu+≫Ag+〉Na+ for transfer of these ions from water to dilute acetonitrile-water. The metallurgically important oxidations of copper, silver, CuS and Cu2 with CuSO4 in water are strongly favored in an enthalpic and free energy sense by the addition of acetonitrile, but addition of acetonitrile also produces a large loss of entropy for the reactions.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00647111
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