K2O + H2O = 2KOH
Ca(OH)2 + SO2 = Ca(SO3) + H2O
LiOH + HCl =LiCl + H2O
Ba(NO3)2 + Na2SO4 = Ba(SO4)2 + 2NaNO3
2Fe(OH)3 = Fe2O3 + 3H2O
Zn + CuCl2 =ZnCl2 +Cu