You went to the store to buy bleach for clothes. On the shelves are bottles of various colors and sizes, but the hand instinctively takes a container with "White" - perhaps the most popular bleach among housewives. And then on the way to the checkout you wanted to read its composition. "Water, then ... And what is sodium hypochlorite?" - these are the standard thoughts of those who accomplished this and came across 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. It may also be called "labarrac / javelin water" or simply "sodium hypochlorite."
The properties
This compound has the appearance of an unstable colorless crystalline substance, which easily decomposes even at room temperature. During this process, oxygen is released, and if the temperature of the conditions is raised to 70 ° C, the reaction is accompanied by an explosion. Sodium hypochlorite dissolved in water is a very strong oxidizing agent. If you add hydrochloric acid to it , then water, sodium chloride and gaseous chlorine are formed. And during the reaction of carbon dioxide with a cooled solution of the substance under discussion, a dilute hypochlorous acid is obtained.
Obtaining sodium hypochlorite
This compound is obtained during the reaction of chlorine gas with sodium hydroxide dissolved in water.
In order to separate
sodium chloride from this mixture
, it is cooled to 0 ° C, then it precipitates. If you continue to keep the 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 pure salt, this crystalline hydrate must be dehydrated in vacuum in the presence of sulfuric acid. However, in this process, sodium hydroxide is successfully replaced by its carbonate. Then the reaction products will be not only the solution of the desired substance and sodium chloride, but also the bicarbonate of the same metal. The substance being discussed now is also obtained by the interaction
of calcium hypochlorite with
sodium carbonate. In such ways it is mined in the laboratory. But in industry, the methods for producing sodium hypochlorite are completely different. There it is produced in two ways: chemical — by chlorinating the hydroxide of this element dissolved in water — and electrochemical — by electrolysis of an aqueous solution of sodium chloride. Each of these processes has its own subtleties of conducting, but they are studied in more detail in institutes.
Application
This substance is an indispensable component in industry. It is easier to talk about this using the table:
| Industry application | What role does NaOCl play in it? |
| Household chemicals | disinfectant and antibacterial |
| fabric bleach |
| solvent deposits of various substances |
| Industry | industrial bleach for fabrics, wood pulps and other materials |
| means for industrial disinfection and sanitary-hygienic processing |
| disinfection and purification of drinking water |
| industrial waste disinfection |
| chemical synthesis |
| The medicine | antiviral, antifungal and bactericidal agent used to treat the skin, mucous membranes and wounds |
Conclusion
Above were given only the main areas where sodium hypochlorite is used. It occupies 91% of the production of all such compounds in the world market. Many other industries are not without this substance. But sodium hypochlorite due to its toxicity requires very careful handling.