A 0.479 g sample of nitrogen, oxygen or neon gas occupies a volume of 265 ml at 157 kpa and 20◦c. what is the molar mass and identity of the gas?

PV = nRT

P = 157 kPa = 157 * 10³ Pa

V = 265 ml = 0.265 l

T = 20°C = 293 K

m = 0.479 g

PV•M = mRT

M = (mRT) / (PV)

M = 0.479 g * 8.314 kPa. l / (mol. K) * 293 K / (157 kPa * 0.265 l)

M ≈ 28.04579 g/mol.

Hence, the Molar Mass of Dinitrogen or Nitrogen Gas is 28 g.