uranium hexafluoride

Question

Uranium hexafluoride is a solid at room temperature, but it boils at 56 Celsius. Determine the density of uranium hexafluoride at 60 Celsius and 0.984 atm.

Answer 1

To my knowledge (and I may be incorrect), but I believe uranium hexafluoride (UF6) sublimes at 56ºC, but nonetheless, let us proceed. If we assume that UF6 in the vapor phase is an ideal gas, (which it most certainly is not), and if we assume that it does "boil" under the conditions stated (which as stated, I don't think it does), then from PV = nRT we have n/V =P/RT = (0.984 atm)/(0.0821 Latm/Kmol)(333K) = 0.03599 mole/L

Density = 352 g/mol x 0.03599 mol/L = 12.7 g/L = 0.0127 g/ml