What type of reaction involves both synthesis and decomposition reactions?

The concept of exchange or double replacement reactions entails the interaction between two compounds leading to the formation of two new compounds. In these reactions, the components of the reactants essentially swap partners, which may involve aspects of synthesis as new compounds are formed and decomposition as the original compounds break apart.

In the context of synthesis, these reactions can create new chemical species. For example, when two ionic compounds react, the cations and anions can exchange places, resulting in the formation of different ionic compounds, which illustrates the synthesis aspect.

At the same time, since the original compounds are decomposed into their constituent ions before the exchange occurs, this aligns with the decomposition aspect of the reaction. Therefore, exchange or double replacement reactions are characterized by their ability to encompass both synthesis of new products and the breakdown of initial reactants, thus fitting the definitions of synthesis and decomposition reactions.