A rolaids tablet contains calcium carbonate, which neutralizes stomach acid. If a rolaids tablet neutralizes 42.15 mL of 0.320 M hydrochloric acid, how many milligrams of calcium carbonate are in a rolaids tablet? CaCO3(s) + 2HCI(aq) -(arrow right) CaCl2(aq) + H2O(I) + CO2 (g)