A 0.465 g sample of an unknown compound occupies 245 ml at 298 k and 1.22 atm. what is the molar mass of the unknown compound? answer: a 0.465 g sample of an unknown compound occupies 245 ml at 298 k and 1.22 atm. what is the molar mass of the unknown compound? 26.3 g/mol 81.8 g/mol 33.9 g/mol 38.0 g/mol 12.2 g/mol

Respuesta :

We know that PV = nRT is the ideal Gas equation.

P = 1.22 atm.
V = 245 ml = 0.245 L
n = 0.465/M and M=molar mass
R = 8.314 J/Kmol = 0.08206 Latm / K mol
T = 298 K

So, putting in the equation:
1.22 * 245/1000 = 0.465/M * 0.08206 * 298
M =  38.677 g/mol