1) CuSO₄+Fe=FeSO₄+Cu
Cu²⁺ +SO₄²⁻ +Fe= Fe²⁺ +SO₄²⁻ +Cu
Cu²⁺ + Fe=Fe²⁺+Cu
2) 2NaHCO₃+H₂SO₄=Na₂SO₄+CO₂↑+2H₂O
2Na⁺ + HCO₃⁻ +H⁺ +SO₄²⁻ = 2Na⁺ + SO₄²⁻ + CO₂↑ + 2H₂O
HCO₃⁻=CO₂↑+2H₂O
3) Zn(OH)₂+NaOH реакции нет
4)SO₂+2KOH=K₂SO₄+H₂↑
SO₂+2K⁺ + 2OH⁻ = 2K⁺ + SO₄²⁻ + H₂↑
SO₄+2OH⁻ = SO₄²⁻+H₂↑
5) Hg(NO₃)₂+2NaF=2NaNO₃+HgF₂↓
Hg²⁺ + 2NO₃⁻ + 2Na⁺ + 2F⁻ = 2Na⁺ + 2NO₃⁻ + HgF₂↓
Hg²⁺ + 2F⁻ = HgF₂↓
6) MgO+2HCl=MgCl₂ + H₂O
MgO+ 2H⁺ + 2Cl⁻ = Mg²⁺ + 2Cl⁻ + H₂O
MgO+ 2H⁺=Mg²⁺ + H₂O