Question

Explain the chemical property of white washing.

Answer 1

Answer:

Whitewash, or calcimine, kalsomine, calsomine, or lime paint is a type of paint made from slaked lime (calcium hydroxide, Ca(OH)2) or chalk calcium carbonate, (CaCO3), sometimes known as "whiting". Various other additives are sometimes used.

Usage as paint

Edit

Whitewashers, photographed by Nicolae Ionescu [cs], 1928

Whitewash cures through a reaction with carbon dioxide in the atmosphere to form calcium carbonate in the form of calcite, a reaction known as carbonation.

It is usually applied to exteriors; however, it has been traditionally used in interiors of food preparation areas, particularly rural dairies, because of its mildly antibacterial properties. Whitewash can be tinted for decorative use and is sometimes painted inside structures such as the hallways of apartment buildings, however it can rub off onto clothing to a small degree. In Britain and Ireland, whitewash was used historically in interiors and exteriors of workers' cottages and still retains something of this association with rural poverty. In the United States, a similar attitude is expressed in the old saying: "Too proud to whitewash and too poor to paint."[1]

Whitewash is especially compatible with masonry because it is absorbed easily and the resultant chemical reaction hardens the medium.