One brand of extra-strength antacid tablets contains 750 mg of calcium carbonate (100.1 g/mol)in each tablet.Stomach acid is essentially a hydrochloric acid solution.Is so much calcium carbonate really needed to neutralize stomach acid? Calculate the volume of stomach acid with a pH of 1.00 that one of these tablets could neutralize,and compare that value with the normal volume of stomach fluid,which usually is about 100.0 mL.One tablet can neutralize __________ mL of stomach acid at a pH of 1.00.

Question

Quizplus · Accepted Answer

To find the volume of stomach acid that can be neutralized, calculate the moles of calcium carbonate in one tablet (750 mg / 100.1 g/mol = 0.00749 mol). The reaction between calcium carbonate and hydrochloric acid is: CaCO3 + 2HCl → CaCl2 + CO2 + H2O. Thus, 1 mole of CaCO3 neutralizes 2 moles of HCl. The pH of 1.00 corresponds to an HCl concentration of 0.1 M. Therefore, 0.00749 mol of CaCO3 can neutralize 0.01498 mol of HCl, which is present in 0.1498 L (or 150 mL) of 0.1 M HCl solution.

One Brand of Extra-Strength Antacid Tablets Contains 750 Mg of Calcium