The experiment requires 13.2 grams of carbon dioxide, which is prepared by the reaction of calcium carbonate and sufficient dilute hydrochloric acid. How much calcium carbonate is needed
CaCO3+2HCl=CaCl2+H2O+CO2↑
44gco2 was obtained by the reaction of 100gcaco3
Now 13.2gco2 is required, so CaCO3 13.2 / 44 * 100 = 30g