A 3.74 gram sample of a certain diatomic gas occupies a volume of 3.48-L at 1.00 atm and a temperature of 45°C.Identify this gas.(R = 0.08206 L.atm/mol.K)

Question

Quizplus · Accepted Answer

The ideal gas law can be used to solve for the number of moles of gas present in the sample:
PV = nRT
n = PV/RT
n = (1.00 atm)(3.48 L)/(0.08206 L*atm/mol*K)(318 K)
n = 0.149 mol

The molar mass of the gas can be calculated using the mass of the sample and the number of moles:
molar mass = mass/number of moles
molar mass = 3.74 g/0.149 mol
molar mass = 25.1 g/mol

Looking at the answer choices, the only gas with a molar mass close to 25.1 g/mol is nitrogen, which has a molar mass of 28.0 g/mol. This is choice B.

A 374 Gram Sample of a Certain Diatomic Gas Occupies a a Volume