Manufacture of Chlorine-Oxygen Compounds

2 Manufacture of Chlorine-Oxygen Compounds 1.7.4.2.1 Hypochlorite Hypochlorite Solutions  

Solutions of sodium and calcium hypochlorite as mixtures with sodium and calcium chloride can be easily obtained by reacting aqueous sodium hydroxide or calcium hydroxide slurries with chlorine  

The solutions ( bleaching solutions ) contain about equimolar quantities of chloride and hypochlorite ions. 

Sodium hypochlorite solutions contain 12 to 15% and calcium hypochlorite 3 to 3.8% of available chlorine. Available chlorine is the quantity of chlorine produced by adding hydrochloric acid, relative to the weight of the product  

The reaction of sodium hydroxide with chlorine is strongly exothermic (AH = 103 kJ/mol). Production can be carried out discontinuously and is monitored by redox potential measurements. Since hypochlorite is easily converted to chlorate at high temperatures, the reaction temperature must be kept below 40°C, for which coolers constructed of titanium are used. The chlorination is generally carried out in such as way that a slight excess of alkali is retained so as to increase the stability of the 

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