\(CuO+2HCl\rightarrow CuCl_2+H_2O\)
\(CuCl_2+2KOH\rightarrow2KCl+Cu\left(OH\right)_2\)
\(Cu\left(OH\right)_2+H_2SO_4\rightarrow CuSO_4+2H_2O\)
\(CuSO_4+BaCl_2\rightarrow CuCl_2+BaSO_4\)
\((1) 2HCl + CuO \to CuCl_2+H_2O\\ (2)CuCl_2+2NaOH \to Cu(OH)_2 +2NaCl\\ (3)Cu(OH)_2+H_2SO_4 \to CuSO_4+2H_2O\\ (4)CuSO_4+Ba(OH)_2 \to BaSO_4+Cu(OH)_2\)