Why does rainwater dissolve limestone

Some types of rock are not easily weathered by chemicals. For example, granite and gabbro are hard rocks that are weathered only slowly. However, some of their minerals do react with the acids in rainwater to form new, weaker substances that crumble and fall away. Coal, oil and natural gas are fossil fuels. When they are used, carbon dioxide and sulfur dioxide escape into the air.

When the sulfur dioxide dissolves in the water in the clouds, it makes acid rain — rainwater that is more acidic than normal. Effect of Limestone. However, acid rain eventually can overcome the buffering capacity of the surface water. Many horizontal and vertical cracks run through limestone. These cracks allow water to pass easily through the rock. Water acts as an acid when it contacts calcium carbonate, dissolving the limestone.

Gypsum is soluble in water and often does not cling to the surface of a limestone rock; however, on buildings or statues that are partially sheltered, the gypsum may precipitate and form a crust on the rock.

As the crust ages, it traps dirt which turns the white mineral a dark color. Begin typing your search term above and press enter to search. Press ESC to cancel.

Buildings constructed from limestone also experience chemical weathering. The image below shows evidence of this. If you've found the resources on this site useful please consider making a secure donation via PayPal to support the development of the site. The site is self-funded and your support is really appreciated.

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