Question #684ed

1 Answer
Jun 21, 2017

You whitewash with a calciumhydroxide emulsion, also called slakes lime #Ca(OH)_2)#

Explanation:

Through contact with carbondioxide in the air, this changes into calciumcarbonate #CaCO_3#:

#Ca(OH)_2+CO_2->CaCO_3+H_2O#

Of course the change happens from the outside in, and the complete process may take much more than a few days, but the calcium carbonate tends to crystalize, and this often gives a shiny finish.