Nitrite ions, reaction temperature effect

Disproportionation of Pu(IV). There are several needs associated witn the occurrence, detection, and mitigation of the disproportionation of Pu(IV) in applied plutonium recovery/ purification procedures. First, there is a great need for much more detailed information concerning the effect of typical process conditions [e.g., temperature, concentration of plutonium, hydrogen ion, nitrate ion, nitrite ion, fluoride ion, other metal ions (e.g., A13+, Fe3+, etc.), etc.] on the occurrence and extent of the reaction ... 

Alternatively, the reaction may proceed through nitrosation by the nitrosonium ion, NO", and subsequent oxidation of the nitroso compound by nitric acid (Scheme 7.3). There is only a small concentration of NO" in dilute nitric acid and so catalytic amounts of sodium nitrite are sometimes added to increase the quantity. This technique is a useful means of effecting smooth, low-temperature nitrations. 

We have reviewed the literature (3-20) and found that many concurrent and consecutive chemical reactions can occur as a result of the interaction between nitrite and sulfite ions. We will summarize the kinetic results of these reactions and present the results of model calculations that give the concentration profile of species produced in this system as a function of reaction time. The effects of temperature, pH, and concentrations of reactant will be demonstrated. 

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