We can use the ideal gas law, PV = nRT to help us solve this problem, where P is pressure, v is volume, n is mols, r is the constant 8.3145, and t is temperature.

Density is simply the mass/volume of an object. So if we can find the mol/volume, we can use the known molar mass of a molecule to convert the concentration to density.

We can find the mol/volume by rearranging the equation such that, P/RT = n/V

- We were given P = 104 kPa which we can convert to Pa: 104 x 10^3
- R is our known constant ffrom above
- T is given, 335 K

We can plug these values in to find n/V: (104 x 10^-3)/(8.3145 x 335) = 37.34 mol/L

The final step is to convert the mols to grams to get the density - we know that the molar mass of NH3 is 17.03 g/mol.

Therefore we can set up an equation, 37.34 mol/L x 17.03 g/mol = 635.87 g/L

Final answer: 635.87 g/L