From Wikipedia, the free encyclopedia
Hypochlorite
In chemistry, hypochlorite is an ion composed of chlorine and oxygen, with the chemical formula ClO−. It can combine with a number of counter ions to form hypochlorites, which may also be regarded as the salts of hypochlorous acid. Common examples include sodium hypochlorite (household bleach) and calcium hypochlorite (bleaching powder, swimming pool "chlorine").
Hypochlorites are frequently quite unstable in their pure forms and for this reason are normally handled as aqueous solutions. Their primary applications are as bleaching, disinfection and water treatment agents but they are also used in chemistry for chlorination and oxidation reactions.
Sodium and Calcium Hypochlorite will produce the same reaction when mixed with an acid, as we have in our stomach. Which will release chlorine gas. It is the chlorine gas that then becames the hypochlorous acid and hydrochloric acid, if there is water to absorb in to,
Reactions of Chlorine Gas With Water
At the same time that chlorine is being used up by compounds in the water, some of the chlorine reacts with the water itself. The reaction depends on what type of chlorine is added to the water as well as on the the pH of the water itself.
Chlorine may be added as to water in the form of chlorine gas, hypochlorite, or chlorine dioxide. All types of chlorine will kill bacteria and some viruses, but only chlorine dioxide will effectively kill Cryptosporidium, Giardia, protozoans, and some viruses. We will first consider chlorine gas, which is the most pure form of chlorine, consisting of two chlorine atoms bound together.
Chlorine gas is compressed into a liquid and stored in metal cylinders. The gas is difficult to handle since it is toxic, heavy, corrosive, and an irritant. At high concentrations, chlorine gas can even be fatal.
When chlorine gas enters the water, the following reaction occurs:
Chlorine + Water → Hypochlorous Acid + Hydrochloric Acid
Cl2 + H2O → HOCl + HCl
The chlorine reacts with water and breaks down into hypochlorous acid and hydrochloric acid. Hypochlorous acid may further break down, depending on pH:
Hypochlorous Acid ↔ Hydrogen Ion + Hypochlorite Ion
HOCl ↔ H+ + OCl-
Note the double-sided arrows which mean that the reaction is reversible. Hypochlorous acid may break down into a hydrogen ion and a hypochlorite ion, or a hydrogen ion and a hypochlorite ion may join together to form hypochlorous acid.
The concentration of hypochlorous acid and hypochlorite ions in chlorinated water will depend on the water's pH. A higher pH facilitates the formation of more hypochlorite ions and results in less hypochlorous acid in the water. This is an important reaction to understand because hypochlorous acid is the most effective form of free chlorine residual, meaning that it is chlorine available to kill microorganisms in the water. Hypochlorite ions are much less efficient disinfectants. So disinfection is more efficient at a low pH (with large quantities of hypochlorous acid in the water) than at a high pH (with large quantities of hypochlorite ions in the water.)
water.me.vccs.edu/concepts/chlorchemistry.html