How does acid rain affect rocks?

Answer 1

Rainwater contains carbonic acid, and chemically reacts with rocks, particularly carbonate ones, dissolving them slowly.

As sulphur and other gases (most commonly found as byproducts of industrial activities) diffuse into clouds, the overall acidity of the rainwater will increase. In small amount this is not a real problem, but when the amounts begin to increase you can get problems such as acid rain. As rainwater is naturally acidic the effects of pure rainwater on rocks will be the same as those with acid rain (although the rate of acid decay of the rock will be higher with acid rain). The effects of the acid rain are most noticeable on limestone (as it is very susceptible to acid erosion due to its high carbon content). The acid will corrode the surface of the rock, allowing to be more easily dissolved into the water and carried away. Over time this can cause serious problems to the overall structure of the rock. If acid rain affects buildings then the outer walls will often be checked to ensure that they will still be able to help support the building.