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I am no chemist, nor did I pick up much understanding of chemical reactions in school. But I would like a basic understanding of how "reactive" and "potent" sulfuric acid is on rock; i.e., whether or not, and if so, how fast it would dissolve or otherwise affect the rock. Now, I know there are various types of rocks, and I'm sure this question could be too broad if not narrowed to some extent. So let me give some specifics.

My questions

Assuming a highly concentrated sulfuric acid (98%; but weaker, if perchance that would be more potent against the particular rock):

  • Will the sulfuric acid affect (dissolve or otherwise) it at all (and the ideal concentration to do so)?
  • If it affects it, then:
    • how fast would it dissolve/otherwise a solid piece of rock (not powder), say 1 cubic inch (though I'm looking for rate answers, so whatever the evidence gives as a rate works)?
    • Is rate affected by pressure (i.e., the rock "sitting" in the acid versus a pressurized spray of the acid on it)?
    • How much faster(?) would it dissolve it if the rock was powdered?
    • What are the general products/results left after the effect?

Igneous Rocks

Sedimentary Rocks

Metamorphic Rocks

(Perhaps the chemically diverse make-up of these rocks makes answering not feasible.)

  • Marble (perhaps reacts similar to limestone, "Geologists use the term 'marble' to refer to metamorphosed limestone"?)
  • Slate

While I have no problems with you giving in your answer the chemical reactions involved, I desire at least a "laymen's" summary of what occurs to each.

(Also, feel free to re-tag if there are some viable tags I was not aware of.)

ScottS
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    Limestone is calcium carbonate so it will be dissolved into hydrogen carbonate and then water and carbon dioxide. Presumably this would leave behind calcium sulfate, which is gypsum. – gannex Apr 17 '16 at 07:19
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    Related for a minor part of the question (not duplicate): http://chemistry.stackexchange.com/questions/47049/why-does-caco3-react-with-hcl-but-not-with-h2so4/47050 – Klaus-Dieter Warzecha Apr 17 '16 at 07:22
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    This is flagged as too broad, and I'm afraid I have to agree with the close flag. – M.A.R. Jun 18 '16 at 08:01

1 Answers1

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This question probably cannot be answered correctly without conducting any experiment.

However, I would not expect that any of the rocks given would be dissolved by highly concentrated sulfuric acid. None of them has a composition that may completely result in the formation of soluble salts when reacting with sulfuric acid.

Presumably (hot?) dilute sulfuric acid may be able to dissolve parts of the rocks if they are powdered. E.g. $\ce{Na2O}$, $\ce{K2O}$, $\ce{MgO}$, and up to a small amount $\ce{CaO}$ and $\ce{Al}$.

Hydrochloric acid would do better since it forms soluble salts not only with Na, K, Mg, Fe, and Al but also with Ca. E.g. it could almost completely dissolve limestone, dolomite, and marble.

aventurin
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  • I agree about an "experiment," but that was why I asked here; somebody must have experimented with sulfuric acid on stone and reported results in a journal/report. My hope is that somebody with access to such info summarizes the results in an answer. My understanding is that sulfuric acid does at least affect limestone and marble, but as Klaus commented on marble, needs to have a resulting protective layer dealt with to continue dissolving. – ScottS Apr 18 '16 at 15:20
  • I don't think that someone tried to do serious research on dissolving the given types of rock in sulfuric acid. In my opinion it just does not make sense. But I am quite sure that there exist result about other aspects of the recaction with sulfuric acid. E.g. effects on the rock surface, or long time effects of exposure to acid rain, which also contains sulfuric acid. – aventurin Apr 18 '16 at 16:59