4Na+O2=2Na2O Na2O + H2O = 2NaOH NaOH+HCl= NaCl+H2O 2.2Na+2H2O= 2NaOH+H2 2NaOH+CuSO4 = Na2SO4 +Cu(OH)2 Na2SO4+2HCl=2NaCl+H2SO4 2NaCl+Ca= CaCl2+2Na