What type of reaction is characterized by the exchange of ions between two compounds?

The reaction characterized by the exchange of ions between two compounds is a double replacement reaction. In this type of reaction, the cations and anions of the reactants switch places, forming two new compounds. This process typically occurs in solutions where soluble ionic compounds react, leading to the formation of new ionic compounds, which may include precipitates, gases, or weak electrolytes.

Double replacement reactions can often be recognized by the general formula:

AB + CD → AD + CB

where A and C are cations, and B and D are anions. The key feature here is the simultaneous exchange of ions, which differentiates them from other reaction types. For example, in a single replacement reaction, one element replaces another in a compound, but the overall mechanism does not involve the exchange of ions between two distinct compounds.

Understanding double replacement reactions is fundamental in predicting the outcomes of chemical reactions, especially in aqueous solutions where ionic interactions play a crucial role in the reaction pathway.