If a nitrogen gas sample occupies a volume of 2.55 L at 22.0 degrees Celsius and 0.860 atm, what is the mass of the N2 gas?

Answer 1

Use PV = nRT and solve for n = number of moles.
Then n = grams/molar mass and solve for grams. You know the molar mass N2 = about 28

Answer 2

PV=nRT
n=PV/RT
n=0.860*2.55/0.08206*(22.0+273.15)
n=2.19/24.2
n=0.0906 mole

0.0906molN*28.00g N/1 mole N
N=2.54g of N2