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