Question

Identify the unknown product (x) in the following reaction:
${\text{Milk of lime }} + {\text{C}}{{\text{l}}_2} \to {\text{x}} + {\text{CaC}}{{\text{l}}_{\text{2}}} + {{\text{H}}_{\text{2}}}{\text{O}}$
A.${\text{Ca}}\left( {{\text{OC}}{{\text{l}}_{\text{2}}}} \right)$
B.${\text{Ca}}{\left( {{\text{OH}}} \right)_{\text{2}}}$
C.${\text{CaO}}$
D.${\text{CaC}}{{\text{O}}_3}$

Answer 1

Milk of lime is also known as calcium hydroxide. It is basic in nature. The reaction given is the synthesis of bleaching powder.

Complete step by step answer:
Milk of lime is the other name for lime water or dilute calcium hydroxide. Limewater is prepared by dissolving calcium hydroxide with water and removing the excess of undissolved base from the solution. The clear and colourless solution with an earthy smell has a pH of $12.4$ .Milk of lime is basic in nature while chlorine is an acidic gas, so neutralizes the basic lime water to form two salts, Calcium Hypochlorite and Calcium Chloride.
The reaction is as follows:
${\text{Ca}}{\left( {{\text{OH}}} \right)_{\text{2}}}{\text{ + C}}{{\text{l}}_{\text{2}}} \to {\text{Ca}}\left( {{\text{OC}}{{\text{l}}_{\text{2}}}} \right){\text{ + CaC}}{{\text{l}}_{\text{2}}}{\text{ + }}{{\text{H}}_{\text{2}}}{\text{O}}$
Hence, x in the reaction is “Bleaching powder” or “calcium hypochlorite” having chemical formula${\text{Ca}}\left( {{\text{OC}}{{\text{l}}_{\text{2}}}} \right)$

Hence option A is correct.

Note:
Bleaching powder is a mild yellowish powder with a strong smell of chlorine gas.
It is soluble in water, but due to the presence of impurities, the solution appears turbid.
Bleaching powder is a potent oxidising agent as is used for the disinfection of water to make it potable.It is also used to bleach dirty clothes as well as to bleach cotton and linen in the textile industry.
The regular bleach used in our households contains 5% bleaching powder having a pH of about 11 and is mildly irritating to the skin.