The analysis in this Demonstration is based upon separating the different cations into groups, following selective precipitations due to the common ion effect, which, in turn, is pH related. Each precipitate must be washed at each separation, according to the standard procedures of analytical chemistry. Our choice is to represent the solution path through the vertical flow line, while the precipitates are represented by horizontal flow arrows. The bifurcations show the division of the solution into different portions. A missing cation does not guarantee the absence of precipitate because of several possible problems (e.g. incomplete precipitation). To highlight this, the precipitate that should not be there but could show up is written in red.

Using the drop-down menu, it is possible to select the general scheme or a scheme limited to specific groups. When "general scheme" is selected, by checking the relevant checkbox it is possible to choose the cations and display the path followed in the analysis. The path should almost always end up through a special reaction uniquely identifying the cation; such unique identification is possible because of cation separation. The VIB Group procedure is not taken into consideration, as in standard lab practice these cations are more easily identified by means of a flame test.