Diagrams Bjerrum

Figure 1.1. A Bjerrum diagram for the relative proportions of carbonic acid system chemical species as a function of pH, for the case where all activity coefficients are equal to 1. pK s are values at 25°C.

Stability diagrams are the simplest and most demonstrative method of estimation of the existence conditions of migration forms vs. pH and Eh (pe) value. They define stability fields of individual migration forms as function of pH at the set Eh value (Bjerrum diagram). Eh at the set pH or simultaneously pH and Eh (pe) value (Pourbaix diagram). 

Example 3.1 Construct Bjerrum diagram for and determine relative concentrations of its migration forms in pure water at its concentration of 10 mole-1" and pH =5. 

Moreover, the equation system of pp. 6 and 8 provides an opportunity to calculate and construct a correlation graph of relative concentrations for various chromium migration forms vs. pH (Figure 3.4). Such graph is the Bjerrum diagram. In a case of limited number of interacting components it is easily constructed using Excel. 

Figure 3.4 Bjerrum diagram for chromium migration forms in pure water.

These equations describe the correlation between concentration of carbonate ions and pH value, which is shown in Bjerrum diagram (Figure 3.19) for standard conditions. This diagram shows that at pH less... 

Figure 3.19 Bjerrum diagram of carbonate equilibrium under standard conditions.

Folkmann, G.E., Hatem, G., Fehrmann, R., Gaune-Escard, M. and Bjerrum, N.J. (1991) Conductivity, thermal analysis, and phase diagram of the system Cs2S207-V205. Inorganic Chemistry, 30, 4057 4061. www.dtu.dk... 

Fig. 7. Structure diagram of the equilibrium swelling conformations charged hydrogels assume in a poor solvent for varying charge fraction f and Bjerrum length...

Closed models of total chemical equilibrium are base in hydrochemical modeling as they are used in all other hydrogeochemical models. They are used at the construction of Bjerrum and Pourbaix diagrams and for the determination of mineral solubility, for computation of equilibrium composition of the water solution or the entire geological medium as a whole by available analytical data. 

Fig. 9. Magnon dispersion for Tb in the ferromagnetic phase along the three principal axis directions. Symbols along the top of the diagram label the directions in the conventional notation shown in fig. 4. Dashed curves labelled PH are [longitudinal acoustic (LA), transverse acoustic (TA), and transverse optic (TO)] phonon branches which interact with the magnons. (After Mackintosh and Bjerrum-Moller 1972.)...

Phase diagram of the NaCl-AlCl system near equimolar conqposltion, with determination of the cryoscopic cmstant, the enthalpy of melting, and oxide contaminants, R.W.Berg, H.A.Hjuler and N.J.Bjerrum, Inorg. Chem., 1984, 23, 557. 

The diagram n as a function of the decimal antilogarithm of the ligand activity (concentration) of the free ligand after complexation (here pCl) is known as the formation curve. The mathematical study of the formation curve permits us to determine the equilibrium constants, A l, K2, K3, K4, etc. (see Sect. 24.3). The formation curve concept is due to J. Bjerrum. It can be extended to other phenomena in solution. 

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