Calcium carbonate is used in many antacid tablets because it reacts with HCl, the primary acid in the stomach, to produce water, calcium chloride, and carbon dioxide. At 37°C and 760 torr, what volume of CO₂ is produced when a person consumes an antacid tablet containing 500.0 mg of CaCO₃ to eliminate excess stomach acid? Assume acid is in excess of the carbonate. (R = 0.08206 L^.atm/K^. mol)

Question

Quizplus · Accepted Answer

First, we need to write the balanced chemical equation for the reaction between calcium carbonate and hydrochloric acid:
CaCO3 + 2HCl → CaCl2 + CO2 + H2O

From the equation, we can see that 1 mole of CaCO3 produces 1 mole of CO2. We can convert the mass of CaCO3 in the tablet to moles using its molar mass:
n(CaCO3) = 500.0 mg / (100.1 g/mol) = 0.004995 mol

According to the stoichiometry of the equation, this amount of CaCO3 will produce the same amount of CO2:
n(CO2) = 0.004995 mol

Now we can use the ideal gas law to calculate the volume of CO2 produced:
PV = nRT
V = nRT/P
V = (0.004995 mol)(0.08206 L atm/mol K)(310 K)/(1 atm)
V = 0.130 L = 130 mL (to 3 significant figures)

Therefore, the volume of CO2 produced is 130 mL, which corresponds to choice D.

Calcium Carbonate Is Used in Many Antacid Tablets Because It