Chemical Forums
Chemistry Forums for Students => High School Chemistry Forum => Topic started by: Iluvatar on February 20, 2006, 10:03:50 PM
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My situation: I am under significant pressure to think up a novel method of breaking an egg for an AP Physics egg-break project. My goal here is to investigate dissolving the shell, hopefully by getting some information from this forum. Note, this will be done in a highschool, and thus, will follow any and all possible safety precautions.
So, my questions to anyone here with knowledge of chemistry are these:
What would be the best chemical with which to dissolve a standard egg shell?
What would be the best commercially available chemical with which to dissolve a standard egg shell?
If I were to use Hydrochloric Acid, what concentration would be required to dissolve the shell relatively quickly (looking for under a minute)?
What concentration of HCL is commercially available?
Any other suggestions involving the chemical destruction of an egg shell?
Any advice/help would be much appreciated.
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I would think that HCl or vinegar would be the ones to try in a high school lab. Although vinegar will probably be a bit too slow for what you are after.
Findind out how the concentration affects the dissolving of the shell could be another interesting experiment in itself. Try a dilute solution and then try more concentrated solutiosn timing how long before the egg shell dissolves.
Usually HCl is about 33% when concentrated, but I doubt you will need this concentration.
Anything acidic should dissolve the eggshell.
Good luck
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We did an experiment involving dissolving an egg shell and vinegar absolutely didnt work, HCl did. 0.1M HCL.
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I thought there was an experiment where you could put an egg in a milk bottle if you soaked it for some time (maybe overnight) in vinegar. Someone once said, “Patience is a virtue”.
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I thought there was an experiment where you could put an egg in a milk bottle if you soaked it for some time (maybe overnight) in vinegar. Someone once said, “Patience is a virtue”.
Patience is a virtue, but in this case the key word is rapidly dissolving an egg shell.
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Well, I was hoping someone had tried something along these lines. From what I've read, vinegar takes about a week to work.
For anyone who cares to know, the point of this activity is to be the end of an eggbreak project, in which as many steps as possible are used to break an egg. Example: I press a switch, which turns on a fan, which blows over a balanced knife, which hits a string which was holding up a weight, which then falls onto the egg.
Of course, this project has been done at my school for many years, and I hope to do something cooler than most, as most ideas have already been used. Thus, instead of flinging, smashing, or piercing an egg, I intend to rapidly dissolve it.
So, I was hoping someone here might be able to show a formula or something showing the correlation between the concentration and speed of dissolving. Guess I'll just have to try it.
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Your high school chem department should have some pretty conc. HCl, around 12M. If you ask politely. ;)
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Well the formula is just hydrochloric acid (or whichever acid you choose) plus calcium carbonate.
In terms of the rate, the usual rules apply, the more concentrated the reagents the quicker the reaction (generally), increased temperature will increase rate (although be careful with heat) and the size of the reagents (example: an eggshell that has been completely crushed up will react quicker than the whole egg).
So in terms of chemistry and rate the quickest way to dissolve the eggshell is to use the most concentrated acid.
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Mike, as we're on this topic. Is there an optimal rate of reaction like in biochem with enzymes? I recall there being a "plateau" at which the rate of reaction peaks and begins to downtrend, factors included temperature/pH and concentration of substrates.
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It won't be the same as an enzyme as enzymes are often destroyed completely at non-optimal pH and temperature. However as the reagents are consumed in the reaction the rate will decrease simply because there are fewer molecules present to react.
In general chemical reaction rates are increased with increasing temperature, concentration, decreasing particle size or by way of a catalyst.
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Right, greater surface area increases rate of reaction. Theoretically, wouldn't the "plateau" be reached when the HCl becomes excess? So not so much the volume but the concentration. Rate of reaction approaches infinity as the concentration of HCl approaches infinity?
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Yes I believe you are correct, there probably would be a point where the concentration difference was great enough to cause little change in the rate. Most often the rate laws that are observed in high school or undergrad science are making the assumption that this is the initial rate over a very short amount of time.