FeSO₄ + K₂CO₃= K₂SO₄ + FeCO₃↓
Fe²⁺ + SO₄²⁻ + 2K⁺+CO₃²⁻= 2K⁺ + SO₄²⁻ + FeCO₃↓
Fe²⁺ +CO₃²⁻= FeCO₃↓
Ba²⁺ + 2F⁻ = BaF₂↓
Ba²⁺ +2CI⁻+ Cu²⁺ +2F⁻ = Cu²⁺+2CI⁻ + BaF₂↓
BaCI₂+ CuF₂ = CuCI₂ + BaF₂↓
или
Ba²⁺ +2NO₃⁻ + Zn²⁺+ 2F⁻ = Zn²⁺+2NO₃⁻ + BaF₂↓
Ba(NO₃)₂ + ZnF₂ = Zn(NO₃)₂ + BaF₂↓