a) Fe(NO₃)₃ + 3HSCN = Fe(SCN)₃↓ + 3HNO₃
Fe³⁺ + 3NO₃⁻ + 3H⁺ + 3SCN⁻ = Fe(SCN)₃↓ + 3H⁺ + 3NO₃⁻
Fe³⁺ + 3SCN⁻ = Fe(SCN)₃↓
б) AgNO₃ + NaI = AgI↓ + NaNO₃
Ag⁺ + NO₃⁻ + Na⁺ + I⁻ = AgI↓ + Na⁺ + NO₃⁻
Ag⁺ + I⁻ = AgI↓
в) SrCl₂ + FeSO₄ = SrSO₄↓ + FeCl₂
Sr²⁺ + 2Cl⁻ + Fe²⁺ + SO₄²⁻ = SrSO₄↓ + Fe²⁺ + 2Cl⁻
Sr²⁺ + SO₄²⁻ = SrSO₄↓