Question

State whether the given statement is true or false:
A solution of a substance X is used for white washing. The reaction of the substance X with water is: ${ CaO }_{ \left( s \right) }+{ H }_{ 2 }{ O }_{ \left( l \right) }\longrightarrow { Ca{ \left( OH \right) }_{ 2 } }_{ \left( aq \right) }$
A. True
B. False

Answer 1

- Hint: The substance used for whitewashing is commonly known as lime or quicklime. It contains calcium and oxygen. We generally use whitewash as a paint for the walls of the house. It has mild antibacterial properties.

Complete step-by-step solution -
The chemical name of the substance used for whitewashing is known as calcium oxide. When calcium oxide is added to water it forms slaked lime which is chemically known as calcium hydroxide.
Thus the given statement is true.

Additional Information: Whitewashing has many advantages. Let us see the applications of whitewashing.
-Whitewash is used as a paint for both interiors and exteriors. Sometimes it is done for decorative purposes and sometimes it is done in rural dairies since it has mild antibacterial properties.
-Whitewash is sometimes used as additives. It is coloured with earths to obtain a wide range of colour such as cream, broken white and a range of brown. Aluminium oxide and magnesium oxide are known as earths.
-Whitewash can be added to trees and especially fruit trees to prevent sun-scald. Sun-scald is the permanent damage caused in the tree barks due to the freezing of the bark following high temperatures during the winter season.
-Whitewash helps in sanitation by coating it over rough surfaces and smoothing them. The antimicrobial properties of whitewash help in maintaining hygiene for animal barns.

Note: Don’t confuse whitewash with lime plaster. Lime plaster is made from sand, water, lime and slaked lime and it is a very old process that was used long ago for building purposes. It has been found as a multipurpose material at different archaeological sites which dates its uses back to 5000 BC.