What distinguishes a double replacement reaction?

A double replacement reaction is characterized by the exchange of ions between two compounds, resulting in two new compounds being formed. In this type of reaction, the cations and anions of the reactants switch partners, effectively leading to the formation of different products while maintaining the overall balance of elements. This process often occurs in aqueous solutions, especially when one of the products is precipitate, water, or a gas.

The other options describe different types of reactions. The first option refers to a synthesis reaction, where two reactants combine to form a single product. The third option describes a single replacement reaction, where one element replaces another in a compound. The last option pertains to a decomposition reaction, in which a single compound breaks down into two or more simpler substances. Understanding these distinctions is crucial in identifying and classifying chemical reactions accurately.