Question

Calculate the osmotic pressure in pascals exerted by a solution prepared by dissolving 1 g of polymer of molar mass 1,85,000 in 450 ml of water at 37°C.

Answer 1

The formula for Osmotic pressure is given by:
 Π = Osmotic pressure = i M R T
       i = 1  for non-electrolytic solutes.
       M = molar quantity of the solute = (1 / 185000) mol /  0.450 Liters
       R = universal gas constant = 8.314 J /K/mol
       T = abs Temperature = 273 + 37 ⁰C = 310⁰ K

  Π =  1.201201 * 10⁻⁵ * 8.314 * 310 = 0.030959 J / Litres
     = 0.030959 N-m / 0.001 m³
     = 30.959  N/m² or Pa

Answer 2

Hey !!

              π = CRT = nB / V (RT) -------> Equation (1)

Number of moles of solute dissolved, nB = 1.0 g / 185,000 g mol⁻¹

           = 1 / 185,000 mol

V = 450 mL = 0.450 L

T = 37°C = 37 + 273 = 310 K

R = 8.314 kPa K⁻¹ mol⁻¹ = 8.314 × 10³ Pa L K⁻¹ mol⁻¹

Now, Substituting these values in equation (1), we get

       π = 1 / 185,000 mol × 1 / 0.45 L × 8.314 × 10³ Pa L K⁻¹ mol⁻¹ × 310 K

FINAL RESULT= 30.96 Pa

Hope it helps you !!