Final answer:
The balanced equation for the reaction between potassium chromate and barium chloride, which results in the precipitation of barium chromate and the formation of soluble potassium chloride, is K2CrO4(aq) + BaCl2(aq) → BaCrO4(s) + 2KCl(aq).
Step-by-step explanation:
When aqueous solutions of potassium chromate and barium chloride are mixed, a chemical reaction occurs where barium chromate, an insoluble solid, precipitates, and potassium chloride remains in solution. This is an example of a precipitation reaction, a type of exchange or metathesis reaction.
The balanced chemical equation for this reaction is written as:
K2CrO4(aq) + BaCl2(aq) → BaCrO4(s) + 2KCl(aq)
To write this equation, one must consider the dissociation of the ionic compounds in water and balance the resulting ions to ensure the law of conservation of mass is satisfied. This means that the number of atoms of each element must be the same on both sides of the equation. In this instance, potassium chromate dissociates into two potassium ions (2K+) and one chromate ion (CrO42-), while barium chloride dissociates into one barium ion (Ba2+) and two chloride ions (2Cl-). Barium ions combine with chromate ions to form the barium chromate precipitate, while potassium and chloride ions remain in solution as potassium chloride.