Final answer:
The pressure exerted by 4.2 g of CO₂ in a 2 L container at 18 °C is 1.21 atm. The volume occupied by 18 moles of CO₂ at a pressure of 2,543 torr and 120 °C is 158.94 L. The correct answer is option (B).
Step-by-step explanation:
Calculating Pressure and Volume for CO₂
To calculate the pressure exerted by 4.2 g of CO₂ in a 2 L volume at 18 °C, we will first convert grams to moles. The molar mass of CO₂ is 44.01 g/mol.
Therefore, 4.2 g of CO₂ is equal to 4.2 g / 44.01 g/mol = 0.095 mol. Using the ideal gas law (PV = nRT), we can find the pressure P. We need to adjust the units of temperature to Kelvin: T(K) = 18 + 273.15 = 291.15 K. The ideal gas constant R = 0.0821 L·atm/K·mol. Thus, P = nRT/V = (0.095 mol)(0.0821 L·atm/K·mol)(291.15 K) / 2 L = 1.21 atm.
Next, to determine the volume occupied by 18 moles of CO₂ at 2,543 torr (which is the same as 2,543/760 atm = 3.35 atm) and 120 °C, we again use the ideal gas law. Convert the temperature to Kelvin: T(K) = 120 + 273.15 = 393.15 K. Now V = nRT/P = (18 moles)(0.0821 L·atm/K·mol)(393.15 K) / 3.35 atm = 158.94 L.
Therefore, the correct answer is (B) Pressure = 1.21 atm, Volume = 158.94 L.