Sodium hypochlorite: properties, production, application

You went to the store to buy a bleach for clothes. On the shelves are bottles of different colors and sizes, but the hand instinctively takes a container with "Belize" - perhaps the most popular bleach among housewives. And then on the way to the ticket office you wanted to read its composition. "Water, then, se ... And what is sodium hypochlorite?" - these are the standard thoughts of those who committed it and stumbled upon an unfamiliar name. In today's article, I will satisfy your curiosity.

Definition

Sodium hypochlorite (formula NaOCl) is an inorganic compound, the sodium salt of hypochlorous acid. Also, it can be called "larbaric / javelin water" or simply "sodium hypochlorite".

Properties

This compound has the appearance of an unstable colorless crystalline substance that decomposes easily even at room temperature. During this process, oxygen is released, and if the temperature of the conditions is raised to 70 ° C, then the reaction is accompanied by an explosion. Dissolved in water sodium hypochlorite - this is a very strong oxidizer. If we add hydrochloric acid to it, water, sodium chloride and gaseous chlorine are formed. And in the reaction of carbon dioxide with the cooled solution of the currently discussed substance, a dilute hypochlorous acid is obtained.

Obtaining sodium hypochlorite

This compound is obtained during the reaction of gaseous chlorine with dissolved sodium hydroxide. To separate sodium chloride from this mixture , it is cooled to 0 ° C., then it falls out as a precipitate. If you continue to hold sodium hypochlorite solution at low temperature (-40 ° C) and then crystallize at -5 ° C, the process will end with the formation of sodium hypochlorite pentahydrate. And to obtain a pure salt, this crystalline hydrate must be dehydrated in a vacuum in the presence of sulfuric acid. However, in this process, sodium hydroxide is successfully replaced by its carbonate. Then the reaction products will not only be the solution of the desired substance and sodium chloride, but also the hydrogen carbonate of the same metal. The substance discussed now is also obtained by the interaction of calcium hypochlorite with sodium carbonate. In such ways, it is extracted in the laboratory. But in industry, the methods for obtaining sodium hypochlorite are quite different. There it is produced in two ways: chemical - by means of chlorination of the dissolved hydroxide of this element - and electrochemical - due to the electrolysis of an aqueous solution of common salt. Each of these processes has its own subtleties, but they are studied in greater detail in institutions.

Application

This substance is an indispensable component in the industry. This is easier to tell with the help of the table:

Conclusion

Above, only the main spheres were used, where sodium hypochlorite is used. It occupies 91% of the production of all such compounds on the world market. Without this substance, there are many other areas of industry. But sodium hypochlorite because of its virulence requires very careful treatment.