CHMB31H3 Chapter Notes - Chapter 5: Nernst Equation, Oxidation State, Electrochemical Cell
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Fuel cell: converts a chemical fuel directly into electrical power. The atomization and ionization of a metal and the hydration enthalpy of its ions all contribute to the value of the standard potential. = k: lnk = vfecell(cid:176) /rt, d sr(cid:176) = vf{ecell(cid:176) (t2) ecell(cid:176) (t1)}/t2-t1. D gr(cid:176) (a+b) = d gr(cid:176) (a) + d gr(cid:176) (b), where d gr(cid:176) = -vfe(cid:176) . Frost diagram or oxidation potential diagram: a plot of ne(cid:176) for the couple. X(n)/x(0) against the oxidation number, n, of the element. oxidation states of an element vary with oxidation number. o. Frost diagrams are conveniently constructed by using electrode potential data; they may be used to gauge the inherent stabilities of different oxidation states of an element and to decide whether particular species are good oxidizing or reducing agents. Pourbaix diagrams show that iron can exist in solution as fe^2+ under acidic reducing conditions such as in contact with soils rich in organic matter.