Question

the marble Statues Often slowly get corroded when kept in open for a long time ?
Assign with suitable explanation

Answer 1

The gaseous oxides (CO2, NO2 and SO2) present in the air as chemical pollutants mix with water in air to form acids such as carbonic acid, nitric acid and sulphuric acid.This acid comes down as acid rain and cause corrosion of marble statues. Calcium carbonate present in marble is transformed into other compounds by reaction with acids as follows:

CO2 + H2O + CaCO3 → Ca(HCO3)2

CaCO3 + H2SO4 → CaSO4 + CO2 + H2O

The compounds formed are water soluble and are easily washed away.
we can take the example of Taj Mahal
which quality is degrading day by day

Answer 2

Answer:

Taj Mahal is an example of corrosion of marble. The discoloration of its marble is due to corrosion.

Air primarily consists of various pollutant gases like carbon dioxide, nitrogen dioxide, Sulphur dioxide

etc which mix with moisture in air to form acids such as carbonic acid, nitric acid and sulphuric acid.

This acid comes down as acid rain and causes corrosion of marble statues and monuments. Marble which

is composed of calcium carbonate reacts with the different acids which is given as follow:-

CO2 + H2O + CaCO3→ Ca (HCO3)2