Sodium hypochlorite

Sodium hypochlorite is a chemical compound with the formula NaClO. It is composed of a sodium cation (Na+) and a hypochlorite anion (ClO−); it may also be viewed as the sodium salt of hypochlorous acid. It is commonly known as bleach or liquid bleach, is frequently used as a disinfectant or a bleaching agent.

Sodium hypochlorite  was first produced in 1789 by Claude Louis Berthollet in his laboratory on the quay Javel in Paris, France, by passing chlorine gas through a solution of sodium carbonate. The resulting liquid, known as "Eau de Javel" ("Javel water"), was a weak solution of sodium hypochlorite. However, this process was not very efficient, and alternative production methods were sought. One such method involved the extraction of chlorinated lime (known as bleaching powder) with sodium carbonate to yield low levels of available chlorine. This method was commonly used to produce hypochlorite solutions for use as a hospital antiseptic that was sold after World War I under the trade names "Eusol" and "Dakin's Solution".
Near the end of the nineteenth century, E. S. Smith patented the chloralkali process: a method of producing sodium hypochlorite involving the electrolysis of brine to produce sodium hydroxide and chlorine gas, which then mixed to form sodium hypochlorite.[1][unreliable source?] Both electric power and brine solution were in cheap supply at the time, and various enterprising marketers took advantage of the situation to satisfy the market's demand for sodium hypochlorite. Bottled solutions of sodium hypochlorite were sold under numerous trade names.