To answer this question, we must first be familiar with the composition of egg shell (the substance that would dissolve). Google returns a discussion that in which the author says that 94% of the egg shell is composed of calcium carbonate. The rest is some more minerals and some protein.
Now, calcium carbonate is a basic substance just like baking soda (sodium bicarbonate). Vinegar, on the other hand, is mostly a 5% solution of acetic acid. I think by now you would have guessed which substance would dissolve the egg shell better.
Of course, it is vinegar. When you add the egg shell in the vinegar, a replacement reaction occurs, forming carbon dioxide in the process. While calcium carbonate is insoluble in water, the resulting compound is soluble. Thus, we see the egg shell as dissolving. The following reaction has occurred:
CaCO3+ 2H+ -> Ca+2 + H2O +CO2
(2H+ from acetic acid)
If you add the egg shell to a baking soda solution instead, the egg shell may not dissolve for a long time for the simple reason that baking soda and calcium carbonate do not react.
Now, calcium carbonate is a basic substance just like baking soda (sodium bicarbonate). Vinegar, on the other hand, is mostly a 5% solution of acetic acid. I think by now you would have guessed which substance would dissolve the egg shell better.
Of course, it is vinegar. When you add the egg shell in the vinegar, a replacement reaction occurs, forming carbon dioxide in the process. While calcium carbonate is insoluble in water, the resulting compound is soluble. Thus, we see the egg shell as dissolving. The following reaction has occurred:
CaCO3+ 2H+ -> Ca+2 + H2O +CO2
(2H+ from acetic acid)
If you add the egg shell to a baking soda solution instead, the egg shell may not dissolve for a long time for the simple reason that baking soda and calcium carbonate do not react.
