You have been given three test tubes of solutions. Determine which one contains hydrochloric acid, sulfuric

You have been given three test tubes of solutions. Determine which one contains hydrochloric acid, sulfuric acid and sodium hydroxide. Write the equation of the corresponding reactions in molecular and other forms.

Alkalis and acids tend to discolor the indicators.

Two acids are given – sulfuric and hydrochloric – and alkali. We put a litmus paper into each test tube. In a test tube with alkali, the paper will turn blue, in test tubes with acids it will turn red.

To determine which test tubes contain sulfuric and hydrochloric acids, add barium chloride to each of them. Barium ions with sulfate – anions give a qualitative reaction – a white precipitate is formed – barium sulfate. In a test tube with hydrochloric acid, the reaction will not occur, since the substances will not react with each other (barium chloride is a salt of hydrochloric acid).

BaCl₂ + H₂SO₄ = BaSO₄↓ + 2HCl.

Ba²⁺ + 2 Cl^1- + 2H¹⁺ + SO₄^2- = BaSO₄↓ + 2H¹⁺ + 2 Cl^1-.

Ba²⁺ +  SO₄^2- = BaSO₄↓.