Final answer:
A double replacement reaction, such as 2 NaBr + BaCl2 → 2 NaCl + BaBr2, involves the exchange of ions between two compounds. In solubility-driven reactions, if the products include a soluble and an insoluble compound, the reaction will proceed, with precipitation indicating completion.
Step-by-step explanation:
The equation 2 NaBr + BaCl2 → 2 NaCl + BaBr2 is an example of a double replacement reaction because the ions in the reactants switch places to form the products. The sodium (Na+) ions replace the barium (Ba2+) ions, and the bromide (Br−) ions replace the chloride (Cl−) ions. This type of chemical reaction is characterized by two ionic compounds exchanging their cations or anions.
In a solubility-driven double replacement reaction like the one involving BaCl2 (aq) and Na2SO4 (aq), solid barium sulfate (BaSO4) is formed as a precipitate. To predict whether a double-replacement reaction like this will occur, understanding the rules of solubility is crucial. When the products include a soluble compound and an insoluble compound, as in the case of forming BaSO4, the reaction proceeds to completion with the formation of a precipitate.