Calcium hypochlorite
Scroll down to download
Calcium hypochlorite has the molecular formula of Ca(ClO)2 and a molecular weight of 142.974 g/mol. Its CAS number is 7778-54-3. Its specific gravity is 1.21 g/cm3. When dissolved in water, it can provide nascent chlorine and oxygen to sterilize pool water or industrial wastewater. The structure of calcium chlorite, Ca(ClO2)2, has been refined from X-ray powder diffraction data using the Rietveld method. The compound crystallizes in the orthorhombic space group Ccca (Ccce), with Z = 4. The structure is based on separate layers parallel to the ac plane, consisting of calcium cations that are coordinated by chlorite anions; the O atoms form almost ideal square antiprisms.
Bleaching powder is actually a mixture of calcium hypochlorite (Ca(ClO)2) and the basic chloride CaCl2, H2O with some slaked lime, Ca(OH)2. The product is generally called “bleaching powder”. It consists of a mixture of calcium chloride (CaCl2), calcium hypochlorite (Ca(OCl)2), and calcium chloride hypochlorite (CaCl(OCl)).
In another method developed for the manufacture of Ca(ClO)2, chlorine gas is reacted with calcium hydroxide:
Ca(OH)2 + 2Cl2 ⇒ Ca(ClO)2 + 2HCl
In this method, it is claimed that the excess HCl is neutralized by excess Ca(OH)2 to form CaCl2. The product is said to be more “neutral” chemically and more stable than that produced by other methods.
Bleaching powder is white or gray white granular material, with a strong irritative odor. Its main component is calcium hypochlorite that exhibits several hydrates, the dihydrate, the trihydrate and the tetrahydrate.
Comments
Post a Comment