why will an eggshell dissolve in the acetic acid of vinegar and not the phosphoric acid of coca cola?

Acetic acid reacts with the egg shell, primarily made of calcium carbonate, CaCO3, to form CO2 and calcium acetate.
Vinegar is roughly 4-6% acetic acid. It takes some time to do this; that is, it isn't a one or two minute reaction.

I THINK (I haven't tried it) that an egg shell will dissolve in a Coca-Cola, also, if it is in a closed system so that the carbonic acid (formed from CO2 dissolved in the liquid) is trapped in the liquid. I expect some time will be required. Leaving the system open will allow the CO2 dissolved in the liquid to escape and the coke loses its fizz and much of the acid content with it. I don't think there is enough phosphoric acid in a coke to do that much damage to an egg shell. In addition, any phosphoric acid there that reacts with the surface of the egg shell will form a precipitate of Ca3(PO4)2 which will protect the egg shell surface somewhat.

You should test the expirement before you actually do it! THEN YOU WOULD BE SOMEWHAT ACCURATE!! MAYBE TRY THAT

To determine why an eggshell will dissolve in acetic acid (vinegar) but not in phosphoric acid (Coca-Cola), we need to understand the chemical composition of these substances.

Vinegar contains acetic acid (CH3COOH), which is a weak acid. When eggshell, primarily made of calcium carbonate (CaCO3), comes into contact with acetic acid, a chemical reaction occurs. The acetic acid reacts with the calcium carbonate and produces carbon dioxide gas (CO2) and calcium acetate (Ca(CH3COO)2). This reaction causes the eggshell to dissolve over time.

On the other hand, Coca-Cola contains phosphoric acid (H3PO4) as one of its main acidic components. However, Coca-Cola is primarily a carbonated drink, which means it contains dissolved carbon dioxide (CO2) gas. When the phosphoric acid in Coca-Cola comes into contact with the eggshell, it can react with the calcium carbonate and form calcium phosphate (Ca3(PO4)2), a type of precipitate. This calcium phosphate helps protect the eggshell surface from further reaction.

Furthermore, Coca-Cola is not as acidic as vinegar. The concentration of phosphoric acid in Coca-Cola is relatively low compared to the acetic acid content in vinegar. This lower acidity level might not be enough to consistently and effectively break down the eggshell.

It is essential to note that the above explanation is based on the chemical composition of these substances. Since the exact formulas of commercial products such as vinegar and Coca-Cola can vary slightly, it is always a good idea to conduct experiments to verify the results for specific situations.