Final answer:
The question deals with stoichiometry, a concept in chemistry that quantifies relationships in a chemical reaction, used to find the mass of a reactant based on the mass of a precipitate formed.
Step-by-step explanation:
The question refers to the calculation involving the precipitation of certain salts from a solution in which reactants are participating in a double-replacement reaction. To calculate the mass of a reactant based on the mass of precipitate formed, we can use stoichiometry, which is a section of chemistry that involves quantitative relationships between reactants and products in a chemical reaction. For example, if 3.06 grams of solid AgCl are recovered, and we know the stoichiometry of the reaction between silver nitrate (AgNO3) and sodium chloride (NaCl), we can calculate the mass of silver nitrate that reacted.