Nitric Acid Oxidations

Dear Kurt,

Thanks for contacting Inorganic Ventures. I have not found a reference on this topic that goes into detail. However, the chemistry of nitric acid is of interest to Inorganic Ventures. The following is my understanding of this chemistry:

There are two reactions that nitric acid follows. In dilute solution the reaction is: NO₃^- + 4H⁺ + 3e- = NO + 2H₂O; E⁰ = 0.96. Assuming you are working in dilute solution then the expression for ΔE (the reduction potential difference between two half cells) is: (ΔE) = 0.0591/n logK, where ΔE is form the oxidation reduction reaction equation, n is number of electrons, and logK is the equilibrium expression for the reaction.

In addition, the half reaction potential (E) for nitric acid may be estimated using the Nernst Equation, where E = E⁰ + 0.0591/3log[(H⁺)⁴ (NO₃^-)]/(P_NO). This equation predicts an increase in the reduction potential (increase in oxidizing ability) as the acidity and molarity of nitric acid increases. Please keep in mind that this assumes a reaction that is not kinetically limited (irreversible).

Please feel free to call with any questions.

Serving you in chemistry,
Paul R. Gaines, Ph.D.
CEO of Inorganic Ventures & Fellow Chemist

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