Question

Why walls gives shiny finish after 2 or 3 days of white washing?

Answer 1

The solution used for white washing of the wall is quick lime(CaO).And when this quick lime is mixed with water it gets converted into slaked lime [Ca(OH)2]
and on exposure to the air it finally gets converted into Calcium carbonate[CaCO3] due to which walls shine...

1.CaO + H2O -----> Ca(OH)2
2.Ca(OH)2 + CO2 -----> CaCO3

Answer 2

Actually white washing of wall contains quick lime(Cao). When it comes to contact with water it converted into calcium hydroxide [ca(oh)2] and on exposed to air it finally converted into caco3.

Cao+h2o - ca(oh) 2

Ca(oh)2 + co2- caco3