a,
Mg+CuSO4-->MgSO4+Cu
Ca(OH)2+CuSO4-->CaSO4+Cu(OH)2
BaCl2+CuSO4-->BaSO4+CuCl2
b
Mg+H2SO4-->MgSO4+H2
Ca(OH)2 +H2SO4-->CaSO4+2H20
BaCl2+H2SO4-->BaSO4+2HCL
c
SO2+2NaOH-->Na2SO3+H20
a,Mg+CuSO4->MgSO4+Cu
Ca(OH)2+CuSO4->Cu(OH)2+CuSO4
BaCl2+CuSO4 ->BaSO4 +CuCl2
b,Mg+H2SO4->MgSO4+H2
Ca(OH)2+H2SO4 ->CaSO4 +2H2O
BaCl2 +H2SO4->BaSO4+2HCl
c,NaOH+SO2->NaHSO3
FeCl3+NaOH -> NaCl+Fe(OH)3