Oxidation-reduction reactions Latimer diagram

Latimer diagram One that shows the reduction potentials connecting a series of species containing an element in different oxidation states, law of mass action States that, for the chemical reaction aA + hB cC + dD, the condition at equilibrium is K JA C JA1, where... 

Perhaps even more important is the effect of hydrogen ion concentration on the emf of a half-reaction of a particular species. Consider the permanganate ion as an oxidizing agent in acid solution (as it often is). From the Latimer diagram above we can readily see that the reduction emf is 1.51 V when all species have unit activity. What is not shown is the complete equation ... 

The standard electrode potentials, E, for such reduction reactions are related to the free energy change for the process by equation 5.3. Since some elements may exist in a number of different oxidation states, it is possible to construct electrode potential diagrams, sometimes called Latimer diagrams, relating the various oxidation states by their redox potentials. Examples are shown in Figure 5.6 for aqueous solutions of some first-row d-block metals and for some actinides in 1 mol dm acid. In cases where the reduction involves oxide or hydroxide ions bound to... 

We begin by placing the substance with the element in the zero oxidation state (in this case, N2) at (0,0) as a reference. The other points are plotted sequentially from this reference point using the reduction half-reactions from the Latimer diagram. For example, the Latimer diagram indicates that E° for N2O-----> N2 equals 1.77 V. The balanced half-... 

Latimer diagrams show successive reduction potmlials of half-reactions that connect various oxidation states of an elanent. Manganese is a good example since it occurs in a number of different oxidalion states from 0 (metal) to -e7 (permanganate) in aqueous solution MnO MnO " (0.564) MnO " - MnOJ" (0.274) MnO Mn02 (4.27) ... 

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