Direct Titration Curve of a Metallic Ion with EDTA

2 Direct Titration Curve of a Metallic Ion with EDTA 

we ll study the direct titration of a metallic ion with EDTA. The reasoning followed in this section can be transposed to inverse titrations without any problem. Recall (Fig. 28.3) that the metallic ion is dissolved in a buffered solution. The pH value is imposed, at least in part, by the equilibrium constant K value  

We have already seen that most of the time titrations must be carried out in a rather alkaline medium. The required buffer that is added may induce the formation of 

The conditional equilibrium constant of the titration reactions takes all these experimental data into account. Knowing an approximate value of its value is sufficient to predict whether or not the titration will be satisfactory. The prediction is carried out by calculating the sharpness index of the titration (see below). 

The titration curve is the diagram pMVadded volume of titrant solution or pMVtp, with 9 the fraction titrated  

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