Is BaSO4 soluble in H2SO4?
The correct answer and explanation is:
BaSO4 (barium sulfate) is not soluble in H2SO4 (sulfuric acid) under normal conditions. In fact, BaSO4 is considered insoluble in water and in most acids. The reason BaSO4 does not dissolve in sulfuric acid is due to its very low solubility in aqueous solutions.
Barium sulfate is a very stable compound, and its low solubility is a result of the strong ionic bonds between the barium ions (Ba²⁺) and sulfate ions (SO₄²⁻). These ionic bonds are not easily broken, which prevents BaSO4 from dissolving. This low solubility is a characteristic that makes BaSO4 useful in certain applications, such as in medical imaging (barium meals for X-rays of the digestive system), where it needs to remain solid and undissolved.
Moreover, sulfuric acid (H2SO4) reacts with soluble barium salts like barium chloride (BaCl2) to produce BaSO4 as a precipitate. In the reaction between sulfuric acid and barium chloride, for instance:
BaCl2(aq) + H2SO4(aq) → BaSO4(s) + 2HCl(aq)
However, when BaSO4 is already in the form of a solid, sulfuric acid does not provide enough energy to break the strong bonds within the BaSO4 crystal lattice, and as a result, it remains insoluble.
In summary, BaSO4 is not soluble in H2SO4 because the sulfate ions in BaSO4 are already in a stable, low-solubility state, and sulfuric acid does not have the capacity to disrupt these bonds effectively.