History
Sodium Hypochlorite was officially discovered around 1785 when a French man named Berthollet discovered a way to bleach things at room temperature using a simple liquid solution containing sodium hypochlorite. He had created the solution by reacting a solution sodium carbonate with chlorine gas, hence producing a weak concoction of sodium hypochlorite. This became known as "eau de Javelle" and is still called that today in France.
The idea of bleaching something, however, is not anything new. The most popular fabric to bleach, cotton, is not naturally white, and therefore must be bleached if a pure white is desired. The ancient Egyptians, even though they didn't have any type of chlorinated solution, used the sun to bleach their cotton by leaving it outside for a long period of time. Even up to the point of the discovery of sodium hypochlorite, the British soaked their cloth in sour milk before laying it out in the sun for two days.
Upon the discovery that chlorine has special bleaching powers, Berthollet proceeded to try using only chlorine as a bleaching agent since it was inefficient to make sodium hypochlorite the way they had produced it. Unfortunately, Berthollet had trouble doing this since Chlorine is a gas in its natural state and therefore was extremely difficult for Berthollet to control and contain.
Finally, chlorine was added to calcium carbonate in order to create a bleaching powder. This method would have worked out great as long as there hadn't been concentrated areas of hypochlorite powder. Unfortunately, the strong bleaching power of hypochlorite would become too strong when concentrated and would end up ruining the cloth that it came in contact with, making it quite ineffective for the purpose it had been intended to serve.
Eventually, new ways of creating sodium hypochlorite were created, hence the widespread use of this compound in today's world, taking the form of bleaches and disinfectants everywhere.