What is the molecular weight of a polymer if 3.50 g are dissolved in enough water to give 252 mL of the solution and give a osmotic pressure of 28.52 mm Hg at 25°C?
2.63 × 10^3 g/mol
28.5 g/mol
6.49 × 10^5 g/mol
8.88 × 10^4 g/mol
9.05 × 10^3 g/mol
To calculate the molecular weight of the polymer, we can use the equation:
Molecular weight (g/mol) = (RT) / (ΠV)
Where:
R = gas constant (0.0821 L·atm/(mol·K))
T = temperature in Kelvin (25 + 273 = 298 K)
Π = osmotic pressure (28.52 mm Hg)
V = volume of the solution in liters (252 mL = 0.252 L)
Plugging in the values, we get:
Molecular weight = (0.0821 L·atm/(mol·K) * 298 K) / (28.52 mm Hg * 0.252 L)
Molecular weight = 9.05 x 10^3 g/mol
Therefore, the molecular weight of the polymer is 9.05 x 10^3 g/mol.