The chemical formula for sodium hypochlorite is NaClO.
Sodium hypochlorite is the sodium salt of hypochlorous acid. It consists of sodium cations, Na⁺, and hypochlorite anions, ClO⁻. The same compound is sometimes written NaOCl; the two formulas represent the same elemental composition and ionic compound.
In dilute aqueous solution, sodium hypochlorite is commonly called chlorine bleach. It is widely used for disinfection, whitening fabrics and treating water. Its antimicrobial action is linked largely to hypochlorous acid formed in solution, whose proportion depends on pH.
The formula is often confused with NaCl, ordinary table salt, or NaClO₂, sodium chlorite. Another important safety distinction is that bleach should not be mixed with acids, because the reaction can release toxic chlorine gas. Mixing bleach with ammonia instead produces chloramines and other hazardous compounds. Claude Louis Berthollet developed an early hypochlorite bleach in Paris in 1789.