Question

Limestone is a naturally occurring mineral rich in calcium carbonate (CaCO₃). In water, calcium carbonate dissolves to form carbonate (CO₃²⁻), a weak base that acts as a buffer. Which would you expect to be more affected by acid rain, an environment rich in limestone or an environment poor in limestone? Choose letter below.

a) the prescience of limestone would not make a difference.
b) an environment rich in limestone would be more affected by acid rain.
c) an environment poor in limestone would be more affected by acid rain.
d) the impact would depend on the type of vegetation present.

Answer 1

Environments poor in limestone would be more affected by acid rain due to a lack of natural buffering capacity. Limestone rich areas have a defense against acid rain, making them more resistant to its damaging effects.

Step-by-step explanation:

An environment poor in limestone would be more affected by acid rain. This is because limestone, which is rich in calcium carbonate (CaCO3), reacts with the sulfuric acid in acid rain. During this reaction, limestone essentially neutralizes the acid, as indicated in the chemical equation:

CaCO3(s) + H2SO4 (aq) → CaSO4(s) + H2O(1) + CO2(g).

When acid rain falls in an area that lacks limestone, there are fewer natural buffers to mitigate the acidity. As a result, the environment is exposed to the full impact of the acid rain, which can lead to the degradation of soil and water quality, negatively affecting both flora and fauna.

Limestone environments, on the other hand, have a natural defense against acid rain. The dissolution of limestone can help to maintain a more neutral pH in the environment. Thus, environments rich in limestone are much more resistant to the effects of acid rain and may experience less ecological damage.