Bleaching powder is a white solid powder containing a mixture of calcium hydroxide, calcium chlorate (I) and calcium chloride. It is manufactured by Hasenclever method on a huge quantity by passing the chlorine gas over a solution of calcium hydroxide.
Properties of Bleaching Powder:
It is pale yellow in color in powdered form having a strong odor of chlorine. It can be dissolved into water but due to the presence of impurities you can never get a clear solution. If placed for long hours, the process of auto-oxidation converts it into calcium chloride and calcium chlorate. Chlorine gas is released by its reaction with excess of dilute acids like sulphuric acid or hydrochloric acid. The quantity of chlorine you obtain from bleaching powder by treating it with excess of CO2 or dilute acids is called available chlorine. About 35% to 38% chlorine is found in a perfect sample of bleaching powder.
Uses of Bleaching Powder
The main uses are:
1- Sterilizing drinking water by disinfecting germs.
2- Production of chloroform.
3- Converting wool into un-shrinkable form.
4- Industries use it as an oxidizing agent.
5- Also used as a bleaching agent in bleaching paper pulps and fabrics