posted by Anonymous .
A 2.800-g mineral sample was analyzed for its calcium carbonate, CaCO3, content by titrating it with hydrochloric acid (the reaction products are calcium chloride, carbon dioxide, and water). The sample required 28.48 mL of a 0.1505 M HCl solution to react completely. Calculate the percent by mass calcium carbonate in the mineral sample.
CaCO3 + 2HCl ==> H2O + CO2 + CaCl2
How many moles HCl were used? M x L = ??
How many moles CaCO3 is equivalent. Use the equation to convert moles HCl to moles CaCO3.
How many grams CaCO3 is that many moles? g = moles CaCO3 x molar mass CaCO3
Now what is the percent CaCO3? That will be (g CaCO3/mass sample)*100 = ??%