Determine the molar mass of Freon-11 gas if a sample weighing 0.597 g occupies 100 cm³ at 95°C and 1000 mmHg (R = 0.08206 L • atm/K • mol, 1 atm = 760 mmHg).

Question

Quizplus · Accepted Answer

First, convert the given conditions to standard units and apply the ideal gas law: PV = nRT. The pressure is given in mmHg, so convert it to atm: 1000 mmHg * (1 atm / 760 mmHg) = 1.3158 atm. The volume is given in cm^3, so convert it to liters: 100 cm^3 = 0.1 L. The temperature is given in °C, so convert it to Kelvin: 95°C + 273.15 = 368.15 K. Now, solve for n (moles of gas) using the ideal gas law: n = PV / RT = (1.3158 atm * 0.1 L) / (0.08206 L•atm/K•mol * 368.15 K) = 0.00434 mol. Finally, calculate the molar mass: molar mass = mass / moles = 0.597 g / 0.00434 mol = 137.6 g/mol, which rounds to 137 g/mol.

Determine the Molar Mass of Freon-11 Gas If a Sample