Question

what is the density f 8L of N2 at 25 degreese C at 760 mmhg?

Answer 1

first, find the moles of N2

n=PV/RT

then, the mass=molecularwtN2*n

finally,
density=mass/8 liters

Answer 2

Use P V = n R T
to find n, the number of mols in a liter

(around 1/22.4 moles/liter but the temp is not zero)

then y
N2 weighs 2*14 = 28 grams/mol

so using my 1 mol/22.4 liters
You would have 28 grams/22.4 liters
= 1.25 grams/liter
you probably want grams / cm^3 though.
there are 1000 cm^3 per liter.
so 0.00125 g/cc using my 22.4 liters per mol approx