Final answer:
Limestone dissolves in acidic groundwater, leading to the formation of caves and other geological features over thousands of years. Acid rain further accelerates the dissolution of limestone structures like buildings and statues.
Step-by-step explanation:
The chemical reaction between limestone and acid in groundwater is indeed responsible for the formation of features such as caves, stalactites, and stalagmites. Limestone, rich in calcium carbonate (CaCO3), dissolves in acidic solutions formed by groundwater containing atmospheric CO2. Over long periods, typically tens of thousands of years, this process can lead to the enlargement of microscopic cracks and eventually form caves. As the water from these acidic solutions seeps into caves and evaporates, the equilibrium shifts and CaCO3 precipitates to form stalactites from the ceiling and stalagmites from the floor.
Additionally, when acid rain, containing strong acids such as sulfuric acid (H2SO4), reacts with limestone, the CaCO3 reacts to form soluble calcium sulfate (CaSO4), contributing to the dissolution of limestone and causing damage over time. This effect is particularly harmful to limestone structures such as buildings and sculptures.