(published on 10/08/07)
(published on 03/03/07)
I’m not sure your answer is as different as you think. Calcium acetate is somewhat water soluble, as you say. It goes into solution primarily as calcium ion Ca+2 and negatively charged acetate ions. So that’s what we showed. Since the acetate was there to begin with, it doesn’t appear in the formula showing what changed in the reaction. I don’t see how you get the reaction formula to balance without making an H2O, which would join the other water molecules already there. It’s true, however, that several different complexes of CO2 and water and its ions are in equilibrium in solution, so the CO2 produced isn’t all in the simple form.
(published on 10/16/07)
Nothing we could say would be as vivid or accurate as what you can opbserve yourslef by doing the experiment. We do have something important to add, however. That oven cleaner can be quite nasty, so be sure to carefully follow all the handling guidelines- gloves, ventilation, etc. Some care is also good with the other cleaners.
(published on 02/23/14)
That is an excellent question to answer by doing the experiment. If I had to guess, some of the membrane that usually sticks on the inside of the shell wouldn't dissolve. But don't take my word for it.
(published on 02/24/14)
It's unclear what you think is inaccurate. So far as I can tell, we say what everybody says except that we describe part of the product as being Ca2+ rather than as calcium acetate. So I guess the issue is to what extent the calcium ion is free in solution and to what extent it's bound to the acetate ions. This website http://calcium.atomistry.com/calcium_acetate.html says on that issue "The electrolytic dissociation of the salt in solution, calculated from the freezing-point lowering, is much greater than that indicated by the electrical conductivity". That sounds like many of the calcium ions may be loosely bound in hydrated complexes with acetate ions. (That's a little like the BeSO4 that I did some of my thesis on. Some of it goes into solution as free ions, some as a non-conducting hydrated neutral complex, and some as neutral molecules.) At this point you probably need a chemist if you want a more detailed description of what state the calcium ion is mostly in in vinegar.
The main point, however, is that other acids (e.g. HCl, citric, ...) also dissolve the eggshells. There's no special role played by the acetate. The acidity is the key. You can find a full discussion with lots of data here: http://en.wikipedia.org/wiki/Calcium_carbonate#Solubility_in_a_strong_or_weak_acid_solution. The solubility depends mostly on the pH and much less on the details of what other ions are around. So the common description of what's in solution as "calcium acetate" is misleading. It's clearer to think of it as the calcium ion.
(published on 04/29/14)