Question

The reaction of $C{l_2}$ with $X$ gives bleaching powder . $X$ is :-
(A). $CaO$
(B). $Ca{\left( {OH} \right)_2}$
(C). $Ca\left( {OC{l_2}} \right)$
(D). $Ca{\left( {Cl{O_2}} \right)_2}$

Answer 1

Hint:Bleaching powder is produced by treating lines with chlorine gas . The reaction that takes place is :
$2C{l_2} + 2Ca{\left( {OH} \right)_2} \to Ca{\left( {OCl} \right)_2} + CaC{l_2} + 2{H_{\,2}}O$ .

Complete step by step answer:
Bleaching powder is chemically known as calcium hypochlorite . It is a pale yellowish powder with a strong smell of chlorine .
It is soluble in water but due to the presence of impurities , the clear solution is never obtained .
The chemical formula of bleaching powder is $CaOC{l_2}$ .
The action of chlorine $\left( {C{l_2}} \right)$ gas on dry slaked lime $Ca{\left( {OH} \right)_2}$ results in the production of bleaching powder .
       $Ca{\left( {OH} \right)_2} + C{l_2} \to CaOC{l_2} + {H_2}O$
Bleaching powder has number of uses :
(1). It is used for bleaching dirty clothes in the laundry as a bleaching agent for cotton and linen in the textile industry .
(2). Also bleaching powder is a strong oxidizing agent so it can be used as an oxidizer in many industries .
(3). It is also used as a disinfectant which is used for disinfecting water to make potable water .
So , the reaction of $Ca\left( {O{H_{\,2}}} \right)$ with $C{l_2}$ gives bleaching powder .
Hence $X$ is $Ca{\left( {OH} \right)_2}$ .
Hence option (B) is the correct answer.

Note:
Bleach is very irritating and it can sometimes be corrosive to the skin , lungs and eyes . It can also burn human tissues internally or externally .A bleach is a 5% solution of sodium hypochlorite (NaClO)with about 1 % sodium hydroxide to stabilize it. While the bleaching powder is the first commonly used solid bleaching agent. It is calcium hypochlorite as Ca(OCl)Cl.