This problem is very vague since no other details are
given. However for the sake of calculation let us assume that the compound is
an ideal gas at STP.
So that the molar volume is: 1 mole = 22.4 L
density = (44.01 g/mol) * (1 mol / 22.4 L) = 1.96 g/L =
1.96 kg/m^3
