granite & limestone

[fresh]

Could you kindly help me with this paragraph ?

 

it reads:

 

Not all lakes are equally affected by acid rain; the damage depends on the kind of bedrock present. Limestone neutralizes acids and has a buffering effect, but granite, composed of silicates, does not undergo any acid-base reaction. So a lake surrounded by granite rock is likely to suffer more damage from acid rain. But granite's lack of reaction with acid also means that gravestone made of granite are going to last longer than those made of limestone.

 

i don't understand why it says 'but granite, composed of silicates, does not undergo any acid-base reaction, So a lake surrounded by granite rock is likely to suffer more damage from acid rain.'; consider granite does not undergo any acid-base reaction why it is likely to suffer more damage from acid rain?

 

and why granite's lack of reaction with acid also means it lasts longer than those made of limestone?

 

thanks.

 

 

 

[swansont]

I think it's saying that the lake will suffer more damage, because the granite will not mitigate the effect of the acid. The runoff that fills the lake will have basically the same pH, as opposed to limestone, which will tend to neutralize the acid.

 

Its lack of reaction means that it won't be weathered much by acid in rain.

[fresh]

thanks, Swansont.

is my understanding skill so poor that i feel confused about the meaning of the mentioned paragraph ? or the paragraph per se makes people confused ?

[swansont]

I had to read it twice; my first impression was the same confusion you exhibited.

 

This says the same thing, but IMO is somewhat clearer.

 

A lake surrounded by granite rock is likely to suffer more damage from acid rain because the granite is composed of silicates and does not undergo any acid-base reaction. Therefore it will not buffer acid rain like limestone will. Granite's lack of reaction with acid also means that gravestone made of granite are going to last longer than those made of limestone.

[studiot]

I agree that that on first reading something appears amiss.

 

What is a lake?

 

That is does it include the container for the water or is it just the water?

 

A good way to be clear is to specify "the water in the lake is likely to suffer.........."

[fresh]

yes, guys, now it is clearer with your elucidation.

[Rajthesmart1234]

The neutrilisation reaction would cause relative damage corresponding to the Ph level of the acids. Thus granite being less rective and probably with less Ph levels may cause more damage and less buffering.