Answer:
Molar mass = 50.4 g/mol
Explanation:
Pressure . Volume = number of moles (n) . R . T°K
This is the Ideal Gases Law where R is the Ideal Gases Constant and T°, Absolute Temperature.
We convert the T°C to T°K → 190°C + 273 = 463 K
R = 0.082 L.atm /mol.K
We need to convert the volume from mL to L → 2160 mL . 1L / 1000 mL = 2.16 L; now we replace:
1 atm . 2.16L = n . 0.082 L.atm /mol.K . 463K
(1 atm . 2.16L) / (0.082 L.atm /mol.K . 463K) = n → 0.569 moles
These moles refers to 2.87 g so let's find out the molar mass:
Molar mass (g/mol) = 2.87 g / 0.0569 mol = 50.4 g/mol