Which of the following types of reactions typically forms a precipitate?

In a double replacement reaction, typically two compounds exchange their ions, and this process can lead to the formation of a precipitate, which is an insoluble solid that emerges from the solution. This occurs when the products of the reaction include a compound that is not soluble in the solvent, often water. The driving force behind this process is the formation of a stable product that can precipitate out of the solution, thus pulling the reaction forward. Common examples include the reactions between sodium chloride and silver nitrate, which produce silver chloride as a precipitate.

In contrast, electrolysis involves the chemical decomposition of a substance due to an electric current and does not focus on ionic exchanges between compounds in a solution. Single-replacement reactions involve an atom or ion in a compound being displaced by another atom or ion, and while they can sometimes produce a solid, they typically do not lead to precipitate formation as frequently as double replacement reactions. Combination reactions involve the combination of two or more substances to form a single product, which rarely leads to precipitate formation since the products are generally soluble. Thus, the nature of double replacement reactions makes them the most likely to result in the formation of a precipitate.