Question

A 1.21 gram sample of an unknown gas is found to occupy a volume of 0.798 L at a pressure of 694 mmHg and a temperature of 31 °C. Assume ideal behavior. The molar mass of the unknown gas is____ g/mol.

Answer 1

According to ideal gas law PV = nRT p is the pressure V is the volume n is number of moles R = 0.0821 L. atm. mol.kt t is the temperature in Kelvin. mass molar mass

pv RT P = 694 atm = 0.91315189474ato ImmHg = I aten 760 n n = (0.91315789474atm )(0.7921) (0.0821 L-atm. modt*>') ( 31+273) K ne 0.02919658311 moles mass = molar mass ho of moles 1-219 molar mass = 0.02919658311 mod = 41.4432 g/mol