Na → NaOH → Na₂SO₄ → NaNO₃.2Na + 2H₂O = 2NaOH + H₂↑;2Na⁰ + 2H₂O = 2Na⁺ + 2OH⁻ + H₂↑.2NaOH + H₂SO₄ = Na₂SO₄ + 2H₂O;
2Na⁺ + 2OH⁻ + 2H⁺ +
SO₄²⁻ =
2Na⁺ +
SO₄²⁻ + 2H₂O;
2OH⁻ +
2H⁺ =
2H₂O;OH⁻ + H⁺ = H₂O.Na₂SO₄ + Ba(NO₃)₂ = 2NaNO₃ + BaSO₄↓;
2Na⁺ + SO₄²⁻ + Ba²⁺ +
2NO₃⁻ =
2Na⁺ +
2NO₃⁻ + BaSO₄↓;SO₄²⁻ + Ba²⁺ = BaSO₄↓.