Question

Which reactioñ is respondible for the shinny finish of the walls after three or four days of white washing?

Answer 1

Reaction between slaked lime I.e. Calcium hydroxide and carbon dioxide.
Here it is,
Ca(OH)2+CO2---------->CaCO3+H2O.

This calcium carbonate is the shiny compound after 3 to 4 days because calcium hydroxide reacts with atmospheric carbon dioxide to form calcium carbonate.

Thanks.
Tripathy