6F Ladder Diagrams
When developing or evaluating an analytical method, we often need to understand
how the chemistry taking place affects our results. We have already seen,
for example, that adding NH3 to a solution of Ag+ is a poor idea if we intend to
isolate the Ag+ as a precipitate of AgCl (reaction 6.29). One of the primary
sources of determinate method errors is a failure to account for potential chemical
interferences.
In this section we introduce the ladder diagram as a simple graphical tool
for evaluating the chemistry taking place during an analysis.1 Using ladder diagrams,
we will be able to determine what reactions occur when several reagents
are combined, estimate the approximate composition of a system at equilibrium,
and evaluate how a change in solution conditions might affect our results.