нужно сделать ионное уравнение
nicl3+naoh-
cao+hcl

NiCl₃ + 3NaOH = Ni(OH)₃ + 3NaCl

Ni³⁺ + 3Cl⁻ + 3Na⁺ + 3OH⁻ = Ni(OH)₃ + 3Na⁺ + 3Cl⁻

Ni³⁺ + 3OH⁻ = Ni(OH)₃

CaO + 2HCl = CaCl₂ + H₂O

CaO + 2H⁺ + 2Cl⁻ = Ca²⁺ + 2Cl⁻ + H₂O

CaO + 2H⁺ = Ca²⁺ + H₂O