physics
posted by Jen .
Calculate the mass of nitrogen present in a volume of 3000 cm^3 if the temperature of the gas is 22 degrees Celsius and the absolute pressure is 2.00 * 10^13 atm, a partial vacuum easily obtained in laboratories. The molar mass of nitrogen (N2) is 28 g/mol. What is the density (in kg/m^3) of the N2

1 mole ocupies 22.4 liters at 273K and 1 atm. At your condtions, 1 mole will occupy (295/273)*1/(2*10^13)= 5.40*10^12 times as much volume, or 1.21*10^14 liters.
You say you have 3 liters, so you have
3/1.21*10^14 = 2.48*10^14 mole
Multiply that by the molar mass (28 g/mole) for the answer. 
The answer provided by DrWLS is the grams. You are also asked for the density.
density = mass/volume = mass/3000 cc .
You will need to convert this to kg/m^3