2NaOH + CuCl₂ = Cu(OH)₂ + 2NaCl
2Na⁺ + 2OH⁻ + Cu²⁺ + 2Cl⁻ = Cu(OH)₂ + 2Na⁺ + 2Cl⁻
Cu²⁺ + 2OH⁻ = Cu(OH)₂