Question

how to calculate the percentage of calcium carbonate in a sea shell

Answer 1

thanks

Answer 2

This is for my Investigatory project

Answer 3

@Jamierox4ev3r is going to try and help you because I have no idea how to do this

Answer 4

ahh its ok

Answer 5

You could take a small sample of the sea shell (weight its initial mass) and react it with hydrochloric acid. From this process you would be able to liberate CO2 from the compound. You would then measure the mass difference when you have determined all of the CO2 has reacted. This would give you the mass of CO2 liberated. Given the stoichiometrically balanced reaction you could say
CaCO3 --> CaO +CO2 (you can ignore the reaction involving HCl)
Given you know the mass of CO2 liberated you can determine the moles of CO2 liberated which is equal to the mole os CaCO3. Convert moles of CaCO3 to mass of CaCO3 and then divide this mass of CaCO3 by the initial mass of the tiny sample of seashell you tested. This will in result give you the percent by mass of CaCO3 in the seashell.

Answer 6

There are means for measuring when all the CO2 has reacted but it involves capturing the CO2 over H2O and determining when the volume change comes to a halt in a graduated cylinder.