Sodium hydroxide (NaOH) is an inorganic compound. It is a white solid and highly caustic metallic base and alkali salt of sodium which is available in pellets, flakes, granules, and as prepared solutions at a number of different concentrations. Sodium hydroxide forms an approximately 50% (by weight) saturated solution with water.
Sodium hydroxide is soluble in water, ethanol, and methanol. This alkali is deliquescent and readily absorbs moisture and carbon dioxide in air.
Sodium hydroxide is used in many industries, mostly as a strong chemical base in the manufacture of pulp and paper, textiles, drinking water, soaps, detergents and as a drain cleaner. It is also used in concrete in the construction industry.