Calcium carbonate, CaCO3(s), the principal compound in limestone, decomposes upon heating to CaO(s) and CO2(g). A sample of CaCO3 is decomposed, and the carbon dioxide is collected in a 250 mL flask. After decomposition is complete, thegas has a pressure of 1.3 atm at a temperature of 31 °C. How many moles of CO2 gas were generated?