Final answer:
Gravimetric analysis is the most appropriate technique for determining the concentration of a salt using a precipitation reaction, as it involves isolating and weighing the precipitated analyte.
Step-by-step explanation:
The most suitable analytical technique for determining the concentration of a particular salt in a solution using a precipitation reaction is gravimetric analysis. In gravimetric analysis, the analyte is separated from a sample through a change in its physical state, such as precipitation. The precipitated analyte is then isolated, usually by filtration, carefully dried, and weighed. Using the mass of the precipitate and the known stoichiometry of the compounds involved, the concentration of the salt in the original solution can be accurately calculated.