ABSTRACT
The fused salt electrochemical cell: Ag; AgCl, KC1; K(2)S(2),O(7),K(2)SO(4); O(2), Pt has been studied. Exact thermodynamic treatment of the chemical reaction, which occurs when current is drawn from the cell, is possible because K(2)S(2)O(7)(1) and AgCl(1) are immiscible, so that no junction potential occurs. Potentials observed at temperatures ranging from 700-800 degrees K for six different mixtures are reported. The Nernst equation is obeyed if it is assumed that the potassium disulphate-potassium sulphate system behaves ideally and that the silver chloride-potassium chloride system deviates slightly, negatively, from ideality. The thermodynamic functions, DeltaG degrees , DeltaH degrees and DeltaS degrees have been calculated from the corrected values of E degrees obtained. The free energy change follows the equation: DeltaG(700-800 degrees K) degrees = -71,680-29.50 T cal mole .
ABSTRACT
Molecular orbital calculations were obtained for one hundred and forty-four versions of the flavin group contained in oxidase enzymes. Ten different structures were considered and the results indicate that the flavin group changes its identity from a pi electron acceptor to a pi electron donor after reduction occurs, regardless of the inductive effect of the attached protein. Furthermore, the calculations suggest both the site for reduction and the mechanism by which it proceeds.
