Sodium Hydroxide (NaOH)
Sodium hydroxide (NaOH), CAS 1310-73-2, also known as lye or caustic soda, is an inorganic compound industrially produced as a 50% solution by the electrolytic chloralkali process in which chlorine gas is also produced. Evaporation of water from this solution yields white crystalline solid sodium hydroxide that readily absorbs moisture from air. Sodium hydroxide dissolves in water to form a colorless solution.
Commercially, sodium hydroxide is used in the manufacture of common items such as soap, paper, rayon, surfactants, and plastic wraps, as well as in the processing of cotton fabric, laundering and bleaching, pickling of metals, oxide coating, electroplating, oil refining, and water treatment. Sodium hydroxide is used in household chemicals such as drain and oven cleaners.
Frequent uses of sodium hydroxide in the laboratory include:
- As a reagent in chemical syntheses and other chemical reactions
- In neutralization and titration of acids
- For storing chromatography media and systems
A highly corrosive compound, sodium hydroxide is harmful if inhaled, ingested, or absorbed through the skin. It is especially destructive to eye tissue, mucous membranes, and the upper respiratory tract. Handlers should wear proper personal protective equipment (PPE), such as nitrile, neoprene, or rubber gloves. Although it is not flammable, the chemical can ignite combustible substances as it absorbs CO2 from the air. Sodium hydroxide should be stored away from water, metals, and strong acids.