Carbonic acid, bicarbonate in water [closed]








**Closed**. This question needs [details or clarity](/help/closed-questions). It is not currently accepting answers.
 
 






---








**Want to improve this question?** Add details and clarify the problem by [editing this post](/posts/112937/edit).




Closed 4 years ago.








[Improve this question](/posts/112937/edit) 



When you add CO2 into water, carbonic acid is created. From carbonic acid (H2CO3), HCO3 + H is formed. When CO2, and H2CO3 leave the water, does HCO3 leave as well, often measure as kH, carbonate hardness?




The chemistry is a bit more complicated than you have described. When $\ce{CO2}$ dissolves in water, most of the carbon species are dissolved $\ce{CO2}$. Carbonic acid, the bicarbonate anion and the carbonate anion are minor carbon species. (See the Wikipedia article - [Carbonic Acid](https://en.wikipedia.org/wiki/Carbonic_acid).)


You can remove the $\ce{CO2}$ by boiling the water, or by sparging (blowing bubbles of a gas containing no $\ce{CO2}$ in the water). But it is only $\ce{CO2}$ that will leave the solution. The equilibriums with carbonic acid, bicarbonate, and carbonate all shift of course as $\ce{CO2}$ is removed. 


 1