This question is about sulfuric acid. Sulfuric acid contains sulfate ions.
Describe the test for the presence of sulfate ions in sulfuric acid. Give the result of the test.

The standard test for sulfate ions (SO₄²⁻) in a solution involves the use of barium chloride (BaCl₂) solution. 1. First, dilute hydrochloric acid (HCl) is added. This is to acidify the solution and to react with and remove any sulfite ions (SO₃²⁻) that might be present, as they would also form a white precipitate with barium chloride and give a false positive result. 2. Next, barium chloride solution is added. If sulfate ions are present, they will react with the barium ions (Ba²⁺) to form barium sulfate (BaSO₄), which is a dense white precipitate. The ionic equation for the reaction is: Ba²⁺(aq) + SO₄²⁻(aq) → BaSO₄(s).