Sodium hydroxide (NaOH) is also referred to as caustic soda or lye is an inorganic compound. Its chemical formula is made of metal ion sodium which is attracted to a non metal ion hydroxide (OH-). This is due to the fact that sodium hydroxide is an ionic compound. It is a solid that is white in color and it is also an alkali salt and a highly caustic metallic base that is available in pellets, granules and flakes. Sodium hydroxide can also be a solution in a number of several concentrations. It forms around fifty percent weight of a saturated solution in water. Sodium hydroxide is a white crystal at room temperature with a melting point of 318 ̊C (604.4 ̊F) and boiling point 1388 ̊C (2530.4 ̊F). Its density is 2.13 g/cm3. Sodium hydroxide is a strong base, and it easy to absorbs CO2 and H2O when exposed. It is used in unclogging drains and in processing food.