Nitrogen Frost diagram

Fig Frost diagram showing the redox states of nitrogen in water at pH = 0 continuous line) and pH = 14 dashed line). 

FIGURE 8-26 Frost Diagram for Nitrogen Compounds in Acid. 

A portion of the Frost diagram for nitrogen is shown in the figure above. The points connected with the bold lines are for basic solution, and the other points are for acid solution. 

The redox chemistry of nitrogen compounds in aqueous solution is illustrated in the Frost diagram in Fig. 1 (see Topic E5 for construction and use). All oxides and oxoacids are strong oxidizing agents, and all oxidation states except -3, 0 and +5 are susceptible to disproportionation. The detailed reactions are, however, mostly controlled by kinetic rather than thermodynamic considerations. In conjunction with oxidizable groups, as in ammonium nitrate NH4N03 or in... 

Latimer diagrams (Appendix B.7) summarize many half-reactions. They also permit construction of Frost diagrams to illustrate the relative potency of species as oxidizing and reducing agents. For example, consider the Latimer diagram for nitrogen in acidic solution ... 

Nitrogen exhibits rich redox chemistry in aqueous solution, as indicated by the Latimer and Frost diagrams in Section 8.1.4. 

If the coordinates of a nitrogen Frost diagram are available (see Exercise 8.3), these data can be used for rapid determination of this potential. The coordinates for HNO2 and N2H5 are (3, 4.36 V) and (—2, 0.46 V), respectively. The slope of the line connecting these points is... 

Fig. 14.6. Potential diagram for nitrogen at pH = 0. A Frost-Ebsworth diagram for nitrogen is given in Figure 7.4c.

Explain how the Frost-Ebsworth diagram for nitrogen (Figure 7.4c) illustrates that NH30H (at pHO) is unstable with respect to disproportionation. 

Figures 8.4b and 8.4c show potential diagrams for phosphorus and nitrogen in aqueous solution with [H ]= Imoldm , and these diagrams are the subject of worked example 8.8. We shall make more use of potential (Latimer) diagrams than Frost-Ebsworth diagrams in later chapters in this book, but the latter can readily be constructed from data...

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