Question

What is the main product formed when chlorine is passed over a dry slaked lime at room temperature?
A.${\text{Ca(Cl}}{{\text{O}}_{\text{2}}}{{\text{)}}_{\text{2}}}$
B.${\text{CaOC}}{{\text{l}}_{\text{2}}}$
C.${\text{CaC}}{{\text{l}}_{\text{2}}}$
D.${\text{Ca(OCl}}{{\text{)}}_{\text{2}}}$

Answer 1

Hint: In the above question, we are asked to find out the main product formed when the chlorine is passed over a dry slaked lime at room temperature. When slaked lime reacts with chlorine, bleaching powder is formed.

Complete answer:
The chlorine used in the formation of bleaching powder comes from common salt. The chemical formula of common salt is ${\text{NaCl}}$. ${\text{NaCl}}$ exists as an important raw material for formation of compounds like caustic soda and bleaching powder. Slaked lime is also used for a variety of purposes, which includes white washing, manufacturing of sugar, usage in sewage treatment, paper industry, pickles and many more.
Bleaching powder is a pale yellowish powder from which a strong smell of chlorine comes. It is soluble in water. The chemical name of bleaching powder is calcium hypochlorite.
Bleaching powder is formed by passing chlorine on dry slaked lime. This process is known as chlor-alkali process.
The chemical equation of slaked lime (${\text{Ca(OH}}{{\text{)}}_{\text{2}}}$) and chlorine (${\text{C}}{{\text{l}}_{\text{2}}}$) is:
${\text{Ca(OH}}{{\text{)}}_{\text{2}}}{\text{ + C}}{{\text{l}}_{\text{2}}}{\text{ }} \to {\text{ CaOC}}{{\text{l}}_{\text{2}}}{\text{ + }}{{\text{H}}_{\text{2}}}{\text{O}}$
where ${\text{CaOC}}{{\text{l}}_{\text{2}}}$is bleaching powder and ${{\text{H}}_{\text{2}}}{\text{O}}$is the water. So, the main product of the above reaction is bleaching powder.

So, the correct option is option B.
Note:
Bleaching powder is used as a cleansing agent to clean clothes and acts as a bleaching agent in the textile industries.
Since bleaching powder is a strong oxidising agent, it is used as oxidiser in industries.
It is also used as disinfectant to make water potable.