# How does rain dissolve limestone? **URL:** \ **Category:** Factual Questions\ **Created:** [May 26, 2011, 11:43am UTC](https://boards.straightdope.com/t/how-does-rain-dissolve-limestone/583267 "2011-05-26T11:43:52Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![figure9](https://avatars.discourse-cdn.com/v4/letter/f/f0a364/32.png) [@figure9](https://boards.straightdope.com/u/figure9)\ **Post date:** [May 26, 2011, 11:43am UTC](https://boards.straightdope.com/t/how-does-rain-dissolve-limestone/583267/1 "2011-05-26T11:43:52Z")
I understand that carbonic acid dissovles calcium carbonate. What I don’t understand is how. I tried google and got lots of info about acid/base reactions, but nothing that shows the chemical equation (process?) for how carbonic acid dissolves limestone. ---
**Author:** ![CalMeacham](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/calmeacham/32/35_2.png) [@CalMeacham](https://boards.straightdope.com/u/CalMeacham)\ **Post date:** [May 26, 2011, 12:34pm UTC](https://boards.straightdope.com/t/how-does-rain-dissolve-limestone/583267/2 "2011-05-26T12:34:14Z")
A quick search turns up this: > **[Yahoo | Mail, Weather, Search, Politics, News, Finance, Sports & Videos](https://www.yahoo.com/)** > > Latest news coverage, email, free stock quotes, live scores and video are just the beginning. Discover more every day at Yahoo! ---
**Author:** ![figure9](https://avatars.discourse-cdn.com/v4/letter/f/f0a364/32.png) [@figure9](https://boards.straightdope.com/u/figure9)\ **Post date:** [May 26, 2011, 4:39pm UTC](https://boards.straightdope.com/t/how-does-rain-dissolve-limestone/583267/3 "2011-05-26T16:39:24Z")
I bow to your google skills. I spent about an hour trying to find that info. Thanks! ---
**Author:** ![Dervorin](https://avatars.discourse-cdn.com/v4/letter/d/eb8c5e/32.png) [@Dervorin](https://boards.straightdope.com/u/Dervorin)\ **Post date:** [May 26, 2011, 6:46pm UTC](https://boards.straightdope.com/t/how-does-rain-dissolve-limestone/583267/4 "2011-05-26T18:46:16Z")
> [@figure9](#): > > I bow to your google skills. I spent about an hour trying to find that info. Thanks! I’m not trying to denigrate your Google skills, but an hour? Really? What were you entering as search terms? I’m honestly curious, because entering “calcium carbonate carbonic acid reaction” gets me to the Wikipedia page on calcium carbonate as the second link, which contains this: Calcium carbonate will react with water that is saturated with carbon dioxide to form the soluble calcium bicarbonate. ``` CaCO3 + CO2 + H2O → Ca(HCO3)2 ``` ---
**Author:** ![figure9](https://avatars.discourse-cdn.com/v4/letter/f/f0a364/32.png) [@figure9](https://boards.straightdope.com/u/figure9)\ **Post date:** [May 27, 2011, 11:48am UTC](https://boards.straightdope.com/t/how-does-rain-dissolve-limestone/583267/5 "2011-05-27T11:48:46Z")
I don’t have my search history, but I tried phrases like “How are caves formed”, “Acid base reactions”, “Limestone”, “Calcium Carbonate”, “Calcium Oxide”, “Carbonic acid” and others. I never thought about putting the two chemicals in the same search term. Seems like the obvious thing to do now that someone has pointed it out.:smack: ---
**Author:** ![thelabdude](https://avatars.discourse-cdn.com/v4/letter/t/dc4da7/32.png) [@thelabdude](https://boards.straightdope.com/u/thelabdude)\ **Post date:** [May 27, 2011, 2:22pm UTC](https://boards.straightdope.com/t/how-does-rain-dissolve-limestone/583267/6 "2011-05-27T14:22:16Z")
Which search engine do you use? I was trying to find the name of the style of dog brush I have been suggesting on Yahoo Answers. I use GoodSearch which gives a pittance to an assistance dog school for every search. It is Yahoo based. It returned several of my Yahoo answers. Bet Google wouldn’t. ---
**Author:** ![figure9](https://avatars.discourse-cdn.com/v4/letter/f/f0a364/32.png) [@figure9](https://boards.straightdope.com/u/figure9)\ **Post date:** [May 27, 2011, 8:37pm UTC](https://boards.straightdope.com/t/how-does-rain-dissolve-limestone/583267/7 "2011-05-27T20:37:40Z")
I use Google. ---
**Author:** ![thelabdude](https://avatars.discourse-cdn.com/v4/letter/t/dc4da7/32.png) [@thelabdude](https://boards.straightdope.com/u/thelabdude)\ **Post date:** [May 28, 2011, 5:36am UTC](https://boards.straightdope.com/t/how-does-rain-dissolve-limestone/583267/8 "2011-05-28T05:36:01Z")
I am thinking Google is less likely to turn up a Yahoo Answers thread than a Yahoo based search engine. ---
**Author:** ![Derleth](https://avatars.discourse-cdn.com/v4/letter/d/b9e5f3/32.png) [@Derleth](https://boards.straightdope.com/u/Derleth)\ **Post date:** [May 28, 2011, 8:20am UTC](https://boards.straightdope.com/t/how-does-rain-dissolve-limestone/583267/9 "2011-05-28T08:20:06Z")
> [@thelabdude](#): > > I am thinking Google is less likely to turn up a Yahoo Answers thread than a Yahoo based search engine. Nah, Google loves Yahoo Answers (which is sometimes bad, given how crazy some of the Answers that site gives can be).