Which process involves determining the concentration of active ingredients in a solution?

Titration is the correct process for determining the concentration of active ingredients in a solution. This analytical procedure involves gradually adding a solution of known concentration (the titrant) to the solution of unknown concentration until a chemical reaction reaches completion, indicated by a color change or other measurable event. By recording the volume of titrant used in the reaction, one can calculate the concentration of the active ingredients in the original solution using stoichiometric relationships.

The other processes are related to handling or applying paint but do not focus on measuring concentration. Mixing involves combining different substances but does not quantify the concentration of active ingredients. Spraying refers to the application method of paints or coatings, allowing for uniform distribution but not analysis of concentration. Coagulation generally pertains to the process of particles clumping together, which can be relevant in specific contexts like paint formulation, but does not relate to measuring concentration directly. Therefore, titration is uniquely suited to the task of determining concentrations in solutions.