Osmotic Pressure

Question

What is the molarity of an aqueous solution of C₆H₁₂O₆ that has an osmotic pressure of 115 mmHg at 19^oC? Answer with 3 decimal places.

Answer 1

π = iMRT

π = osmotic pressure = 115 mm Hg x 1 atm / 760 mm Hg = 0.151 atm

i = van't Hoff factor = 1 for C6H12O6 (glucose) which is a non electrolyte

M = molarity = ?

R = gas constant = 0.0821 Latm/Kmol

T = temperature in Kelvin = 19C + 273 = 292K

Solving for M (molarity), we have ...

M = π / (i)(R)(T)

M = 0.151 atm / (1)(0.0821 Latm/Kmol)(292K)

M = 0.00630 M = 0.006 M (3 decimal places)