Question

Bleaching powder is made up of :
A. Lime and chlorine
B. soda ash and chlorine
C. chlorine and charcoal
D. none of these

Answer 1

Hint: Bleaching powder is an inorganic commercial product . The chemical name of bleaching powder is calcium hypochlorite with formula $Ca{(OCl)_2}$ or $CaOC{l_2}$and molar mass $142.98gmo{l^{ - 1}}$. It is a mixed salt and is represented as $Ca{(OCl)_2}.Ca{(OH)_2}.CaC{l_2}.2{H_2}O$ . The compound is very complex . It is also called Chlorine powder or chlorinated lime. When bleaching powder decomposes it liberates oxygen. It decomposes when exposed to air.

Complete answer:
 $2CaOC{l_2} \to 2CaC{l_2} + {O_2}$
This is yellowish white powder which has the smell of chlorine. It is soluble in water . Its clear solution can not be obtained due to the presence of free lime. It is used for bleaching washed clothes in laundry ,acts as a disinfecting agent for water .It is also important for the manufacture of chloroform. Bleaching powder is a strong oxidizing agent so used as an oxidizer in many industries. It is used to bleach wood pulp in the paper industry.
 Bleaching powder is produced by the reaction of calcium hydroxide with chlorine. Calcium hydroxide is also known as slaked lime. When chlorine gas is passed over the dry slaked lime thus bleaching powder and water is produced.
                   \[Ca{(OH)_2} + C{l_2} \to Ca\left( {OCl} \right)Cl + {H_2}O\]
So option A is correct which is lime and chlorine .Bleaching powder is made up of lime and chlorine.

Note: Here we have studies about the composition of bleaching powder. We also come to know about chemical and physical properties of bleaching powder and its uses in daily and industrial life. It is prepared by the action of chlorine on dry slaked lime. A good sample of bleaching powder contains $35\% - 38\% $ of available chlorine.