Respuesta :

 T = 22.0 + 273.15 =295.15 K 
Molar mass Cl2 = 70.906 g/mol 
d = molar mass x p / RT = 70.906 x 1.00 / 0.0821 x 295.15 = 2.93 g/L
Hope this isn't to much? If it doesn't help you know where to find me :)