Complete the molecular equations of possible reactions in solutions, and write down the corresponding ionic equations.

Salt sodium sulfate and hydrochloric acid. As a result of the reaction, substances are formed: sodium chloride salt and sulfurous acid.
Na₂SO₃ + 2 HCl = 2 NaCl + H₂SO₃
2 Na⁺ + SO₃²⁻ + 2 H⁺ + 2 Cl⁻ = 2 Na⁺ + 2 Cl⁻ + H₂O + SO₂
SO₃²⁻ + 2H⁺ = H₂O + SO₂.
Nitric acid reacts chemically with the sodium sulfide salt. As a result of a chemical reaction, we get sodium nitrate salt and hydrogen sulfide.
2 HNO₃ + Na₂S = 2 NaNO₃ + H₂S
2 H⁺ + 2 NO₃⁻ + 2 Na⁺ + S²⁻ = 2 Na⁺ + 2 NO₃⁻ + H₂S
2 H⁺ + S²⁻ = H₂S
A chemical reaction takes place between substances such as sulfuric acid and sodium carbonate salt. As a result of the reaction, substances are formed: sodium sulfate salt and carbonic acid. The molecular equation of the reaction can be written as follows:
H₂SO₄ + Na₂CO₃ = Na₂SO₄ + H₂CO₃
2 H⁺ + SO₄²⁻ + 2 Na⁺ + CO₃²⁻ = 2 Na⁺ + SO₄²⁻ + H₂O + CO₂
2 H⁺ + CO₃²⁻ = H₂O + CO₂.