[tex]Na+H _{2} O=NaOH+ \frac{1}{2} H _{2} \\ \\ Na _{2}O+H _{2} O=2NaOH \\ \\ 2NaOH+ SO _{2} =Na _{2} SO _{3} +H _{2} O \\ \\ 2NaOH+H _{2} SO _{4} =Na _{2} SO _{4} +2H _{2} O \\ \\ 2NaOH+CuSO _{4} =Cu(OH) _{2} +Na _{2} SO _{4} \\ \\ ---------------------------------- \\ [/tex]
a=Na ;b=Na2O;c=Na2SO3 ;d=Na2SO4 ;e=CuSO4 ;i=H20
