Chemical Properties and Applications

What is the chemical nature of sodium hydroxide?

Sodium hydroxide, commonly known as caustic soda or lye, is an inorganic compound composed of sodium cations (Na⁺) and hydroxide anions (OH⁻). It is a white, hygroscopic solid that readily dissolves in water, releasing significant heat. Its high pH (typically 13–14 in aqueous solution) makes it a powerful base used in neutralisation reactions, cleaning processes, and the production of soaps, textiles, and paper. In pharmaceutical and biotech settings, it is used to adjust pH in formulations and buffer systems.

How is sodium hydroxide used in laboratory and industrial settings?

In laboratories, sodium hydroxide is employed in titrations, protein denaturation, and cleaning glassware. It is also used in the synthesis of various organic compounds and in the preparation of reagents such as sodium borohydride. Industrially, it is a key raw material in the chlor-alkali process, where it is produced alongside chlorine and hydrogen gas. In biotechnology, it is used in cell lysis protocols and in the purification of recombinant proteins. Due to its reactivity with acids and certain metals, it must be stored in sealed containers away from moisture and incompatible substances.

Related concepts

Sodium hydroxide is often used alongside other strong bases such as potassium hydroxide (KOH) and ammonia. It is regulated under REACH and GHS, with associated safety data sheets (SDS) and handling guidelines. Common grades include ACS, USP, and EP, with purity levels critical for pharmaceutical and research applications.