GRADE 9 CHEMISTRY 10 POINTS..?

Dry the egg shell. Crush it up and weigh it. Add dilute HCl. Let stand for a few hours. Filter off the stuff that did not dissolve. Rinse the solids in the filter and collect with the HCl liquid. Evaporate the HCl liquid. Weigh the solids. Calculate the moles of CaCl2. Convert to g of CaCO3. This should be close to your original weight if your umption is correct.