One brand of extra-strength antacid tablets contains 750 mg of calcium carbonate (100.09 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

The pH of 1.00 corresponds to a hydrogen ion concentration of 0.1 M. The reaction between calcium carbonate and hydrochloric acid is: CaCO3 + 2HCl → CaCl2 + H2O + CO2. One mole of CaCO3 neutralizes 2 moles of HCl. 750 mg of CaCO3 is 0.0075 moles, which can neutralize 0.015 moles of HCl. Therefore, it can neutralize 0.015 moles / 0.1 M = 0.15 L or 150 mL of stomach acid.

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