You know that an unlabeled bottle contains an aqueous solution of one of the following: AgNO3, CaCl2, or Al21SO423. A friend suggests that you test a portion of the solution with Ba1NO322 and then with NaCl solutions. According to your friend's logic, which of these chemical reactions could occur, thus helping you identify the solution in the bottle? (a) Barium sulfate could precipitate. (b) Silver chloride could precipitate. (c) Silver sulfate could precipitate. (d) More than one, but not all, of the reactions described in answers a–c could occur. (e) All three reactions described in answers a–c could occur.

Key Concepts

Precipitation Reactions

Precipitation reactions occur when two soluble salts react in solution to form an insoluble compound, known as a precipitate. This process is driven by the formation of a product that is less soluble than the reactants, leading to its separation from the solution. Understanding the solubility rules helps predict which combinations of ions will result in a precipitate.

Solubility Rules

Solubility rules are guidelines that help predict whether a compound will dissolve in water. For example, most sulfates are soluble, except for those of barium, lead, and calcium, while chlorides are generally soluble except for silver and lead. Knowing these rules is essential for determining which reactions will produce precipitates in the given scenario.

Ionic Compounds and Their Reactions

Ionic compounds, such as AgNO3, CaCl2, and Al2(SO4)3, dissociate into their constituent ions in aqueous solutions. When mixed with other ionic solutions, these ions can recombine to form new compounds. Identifying the ions present in the original solution allows for predicting possible reactions with Ba(NO3)2 and NaCl, leading to the formation of precipitates like barium sulfate or silver chloride.