The pressure of O₂ in a 15.0 L flask is 322 mm Hg at 44 °C.What mass of O₂ is in the flask? (R = 0.08206 L⋅atm/mol⋅K) A) 0.244 g B) 5.80 g C) 7.82 g D) 15.2 g E) 56.3 g

Question

Quizplus · Accepted Answer

First, convert the pressure from mm Hg to atm: 322 mm Hg * (1 atm / 760 mm Hg) = 0.4237 atm. Convert the temperature from Celsius to Kelvin: 44 °C + 273.15 = 317.15 K. Use the ideal gas law: PV = nRT. Solve for n (moles of O2): n = PV / RT = (0.4237 atm * 15.0 L) / (0.08206 L⋅atm/mol⋅K * 317.15 K) = 0.244 mol. The molar mass of O2 is 32.00 g/mol, so the mass is 0.244 mol * 32.00 g/mol = 7.82 g.

The Pressure of O2 in a 15

The Pressure of O₂ in a 15