why does it take 1 year to dissolve an eggshell in coke?

-------------------------------------------------------

answers:
Ronald 7 say: It does indeed
That was one boring year !!
But I have made up for that by joining Yahoo Answers
I like to help people
I am a very nice guy
Coke, as in Coca Cola, is going back to its original taste by the way
They are putting Aspartame into it to replicate the original taste of Cocaine
Anyway, besides that, Coca Cola has a lot of Phosphoric acid, which although Slow working will burn its way though anything
-
busterwasmycat say: Does it? I never tried. Phosphoric acid is a weak acid so will not dissolve a base salt very quickly. I find it difficult to believe that it would take a year. I suspect that the real problem is that the concentration of phosphoric acid is too low to completely dissolve the eggshell. The fluid-shell reaction achieves equilibrium and then basically nothing else happens. If the shell dissolves after that, it isn't from the original acidity. That gets consumed pretty fast.
-
Roger the Mole say: If your eggshell does not dissolve in a day or two it is because you didn't use enough Coke, and it won't dissolve after a year passes either.
-
pisgahchemist say: Coke and eggshells....

Coca-Cola, indeed, many cola drinks are somewhat acidic due to the dissolved CO2 and some phosphoric acid, H3PO4. The trace amount of phosphoric acid gives the carbonated drink a little extra "bite." If left out, most of the CO2 will leave the cola drink and what little dissolved CO2 is left will reach equilibrium with the CO2 in the air.
...... CO2(aq) + H2O(l) <==> H+ + HCO3^-
...... H+ makes the solution acidic.

The interweb jury is still out on how long it takes to dissolve an eggshell in Coke, but the effect is due primarily to the phosphoric acid which doesn't migrate out of solution as does CO2. The eggshell is mostly calcium carbonate, CaCO3, and carbonate compounds react with acids.
...... CaCO3(s) + H3PO4(aq) --> CaHPO4(aq) + CO2(g) + H2O(l)

But there's a hitch in that giddy-up. There is very little phosphoric acid in a cola drink, and there may not be enough to actually dissolve all the eggshell. One would need to know the concentration of H3PO4 and the mass of CaCO3 to make a decent prediction. It's also possible that the eggshell dissolves simply because calcium carbonate is ever so slightly soluble in water.
-
Remy say: probably
-
:; say: Probably because the coke went flat and took longer use bleach
-
Robin say: its takes 18 hours
-
ztsek say: zkysagmx
-