1) Ba(OH)₂+Cu(NO₃)₂=Ba(NO₃)₂+Cu(OH)₂↓
Ba²⁺ + 2OH⁻ + Cu²⁺ + 2NO₃⁻ = Ba²⁺+ 2NO₃⁻+ Cu(OH)₂↓
2OH⁻+ Cu²⁺= Cu(OH)₂↓
2) K₂CO₃+H₂SO₄=K₂SO₄+CO₂↑+H₂O
2K⁺+ CO₃²⁻+ 2H⁺ + SO₄²⁻=2K⁺ + SO₄²⁻+CO₂↑+H₂O
CO₃²⁻+2H⁺ = CO₂↑+H₂O
3) Al(OH)₃+3HCI=AICI₃ + 3H₂O
Al(OH)₃ + 3H⁺+ 3CI⁻= AI³⁺+ 3CI⁻ + 3H₂O
Al(OH)₃ + 3H⁺ = AI³⁺+ 3H₂O