A container of carbon dioxide gas has a volume of 50.0 L. When originally purchased, the tank guage showed a pressure of 10.0 atm at 25.0 C. After one month's use, the tank pressure was 4.70 atm at 15.0 C. How many grams of CO2 were used during the month? molar mass of CO2 is 44.00995 g/mol.