Answer:
Molar mass of the polymer is 8055.6 g/mol
Explanation:
Let's apply the colligative property of osmotic pressure:
π = M . R . T where
π is the osmotic pressure
M is molarity (mol /L)
R is the universal gases constant (0.082 L.atm/mol.K)
T is Absolute T° (°C + 273)
T° K = 294.9K
Let's determine our unknown value in molarity
Molarity is mol /L and mol is mass / molar mass
Molarity is (mass / molar mass) / volume, that can be written as:
(mass / molar mass) . 1 / volume
M = (0.654 g / molar mass) . 1 / 0.0409 L
Remember that volume must be in Litters. → 40.9 mL . 1 L/1000 mL = 0.0409 L
0.048 atm = (0.654 g / mol mass) .1 / 0.0409 L . 0.082 L.atm/mol.K . 294.9K
0.048 atm / 0.082 L.atm/mol.K . 294.9K = (0.654 g / mol mass) .1 / 0.0409 L
1.98×10⁻³ L/mol = (0.654 g / mol mass) .1 / 0.0409 L
1.98×10⁻³ L/mol . 0.0409 L = 0.654 g / molar mass
8.12×10⁻⁵ mol = 0.654 g / molar mass
Molar mass = 0.654 g / 8.12×10⁻⁵ mol → 8055.6 g/mol
