Question

blood isnt the only natural system that uses acid/base buffers.
limestone is made of calcium carbonate. how would you expect the ph of a lake with limestone bedrock to compare to other lakes after several years of acid rain?
extra carbon dioxide in the blood is removed by the lungs. how would extra carbon dioxide in a lake be removed?

Explanation:

• For the first question: Calcium carbonate (\(CaCO_3\)) in limestone can react with acids (from acid rain). The reaction \(CaCO_3 + 2H^+

ightarrow Ca^{2+}+H_2O + CO_2\uparrow\) consumes \(H^+\) ions. So, a lake with limestone bedrock would have a higher (less acidic) pH compared to other lakes after acid - rain exposure.

• For the second question: In a lake, extra carbon dioxide (\(CO_2\)) can be removed through processes like diffusion into the atmosphere (similar to how gas exchange occurs at the air - water interface) and photosynthesis by aquatic plants (where \(CO_2\) is used as a reactant: \(6CO_2+6H_2O

ightarrow C_6H_{12}O_6 + 6O_2\)).

Answer:

• The pH of a lake with limestone bedrock would be higher (less acidic) than other lakes after acid rain.
• Extra carbon dioxide in a lake can be removed by diffusion into the atmosphere and by photosynthesis of aquatic plants.