The acid that is believed to be mainly responsible for the damage of Taj Mahal is

We need to identify the acid mainly responsible for the damage to the Taj Mahal. The yellowing and deterioration of the Taj Mahal’s white marble is primarily caused by acid rain. Located in Agra, the monument is surrounded by several industries, including the Mathura oil refinery, which emit gases responsible for this phenomenon.

The burning of fossil fuels releases $$SO_2$$ and $$SO_3$$ into the atmosphere. These gases react with water vapour to form sulfuric acid $$H_2SO_4$$ through a series of reactions:

$$SO_2 + H_2O \rightarrow H_2SO_3$$

$$2SO_2 + O_2 \rightarrow 2SO_3$$

$$SO_3 + H_2O \rightarrow H_2SO_4$$

Marble is primarily composed of $$CaCO_3$$, and sulfuric acid reacts with it according to the equation $$CaCO_3 + H_2SO_4 \rightarrow CaSO_4 + H_2O + CO_2$$.

This process, often referred to as “Marble cancer” or “stone leprosy,” produces powdery $$CaSO_4$$ that flakes off, leading to the deterioration of the monument.

Option A: sulfuric acid.