L
$NaOH+CO_2---->Na_2CO_3+H_2O$
-----------------------------------------------
$caco_3---------to---------->cao+co_2$
---------------------------------------------------------
Ca(OH)2+CO2--->CaCO3+H2O
.................................................
$CaO+HCl------->CaCl_2+H_2O$
----------------------------------------------------
$Al(OH)_3--------to-------->Al_2O_3+H_2O$
--------------------------------------------