The chemical formula of bleaching powder is CaOCl2. It is also called as the chloride of lime.
PREPARATION OF BLEACHING POWDER
In this process, Chlorine gas(produced from the chlor-alkali process) is passed over dry slaked lime to produce bleaching powder:
PROPERTIES OF BLEACHING POWDER
It is a pale yellowish powder having a strong smell of chlorine.
It is soluble in cold water. The small insoluble portion left behind on dilution is the lime present in it.
Bleaching powder reacts with dilute acids to produce chlorine.
When bleaching powder is treated with an excess of a dilute, all the chlorine present in it is liberated.
For example, when bleaching powder is treated with an excess of dilute sulphuric acid, all the chlorine present in it liberated:
Here, the chlorine produced by the action of dilute acid on bleaching powder acts as a bleaching agent. Thus, the real bleaching agent present in bleaching powder is chlorine.
USES OF BLEACHING POWDER:
It is used for bleaching cotton and linen in textile industry and for bleaching wood pulp in paper industry.
It is also used for bleaching washed clothes in laundry
It is used for disinfecting drinking water supply to make it potable. That is, for making drinking water free from germs.
It is used for the manufacture of chloroform (CHCl3).
