The chemical reaction K2SO4 + BaCl2 → 2KCl + BaSO4↓ (aq.) (aq.) (aq.) (solid) is an example of:

The chemical reaction K2SO4 + BaCl2 → 2KCl + BaSO4 is a classic example of a double displacement reaction, also known as a double replacement or metathesis reaction [1]. In this process, the reacting ionic compounds exchange their constituent ions: the potassium (K+) and barium (Ba2+) cations switch their anion partners (sulfate SO4 2- and chloride Cl-). Specifically, the barium ions combine with sulfate ions to form barium sulfate (BaSO4), which is insoluble in water and precipitates out as a solid. Meanwhile, potassium chloride (KCl) remains dissolved in the aqueous solution. Because an insoluble solid is formed from two aqueous solutions, this reaction is also categorized as a precipitation reaction. This type of reaction is characterized by the mutual exchange of ions between two compounds to form two new compounds.

Sources

1. [1] Science , class X (NCERT 2025 ed.) > Chapter 1: Chemical Reactions and Equations > Activity 1.9 > p. 11