Question

Which of the following reactions is known as slaking of lime?
A.${\text{CaC}}{{\text{O}}_{\text{3}}} \to {\text{CaO}} + {\text{C}}{{\text{O}}_2}$
B.${\text{CaO}} + 2{\text{HCl}} \to {\text{CaC}}{{\text{l}}_2} + {{\text{H}}_2}{\text{O}}$
C.${\text{Cac}}{{\text{O}}_3} + {{\text{H}}_2}{\text{O}} \to {\text{Ca}}{\left( {{\text{OH}}} \right)_2} + {\text{C}}{{\text{O}}_2}$
D.${\text{CaO}} + {{\text{H}}_2}{\text{O}} \to {\text{Ca}}{\left( {{\text{OH}}} \right)_2}$

Answer 1

Hint:The reaction in which slaked lime is produced is known as slaking of lime. Slaked lime is also known as calcium hydroxide.It is a colorless crystal or white powder and is produced when quicklime is mixed, or slaked with water.

Complete step by step answer:
The reaction in which slaked lime is produced is known as slaking of lime. Slaked lime is also known as calcium hydroxide.
The reaction of calcium oxide or quicklime with water produces slaked lime.
Adding water to quicklime produces a tremendous amount of heat. Thus, slaking of lime is an exothermic reaction. The reaction is carried out in slaking pits.
The slaked lime or calcium hydroxide produced in this reaction dissolves in water and produces an alkaline solution which is known as limewater.
The reaction is as follows:
${\text{CaO}} + {{\text{H}}_2}{\text{O}} \to {\text{Ca}}{\left( {{\text{OH}}} \right)_2}$
Thus, the correct option is option (D).

Additional Information:
The uses of slaked lime or calcium hydroxide are as follows:
-Slaked lime is used for white washing i.e. giving white shiny layers to walls.
-Slaked lime is used in sewage treatment plants as a water flocculant.
-Slaked lime is used in manufacturing of paper, sugar, paan, papadum, tobacco, etc.
-Slaked lime is used in preservation of pickles.
-Slaked lime is used as a digestive aid.
-Slaked lime is used in removing the cellulose hull from maize kernels.

Note:
The properties of slaked lime are as follows:
Slaked lime is colourless and white powder in appearance.
Slaked lime does not have any odour.
Slaked lime is soluble in water, acids and glycerols but insoluble in alcohol.
Slaked lime is alkaline in nature.