Question

A solution containing 10g of glucose has osmotic pressure 3.84atm if 10g more glucose is added to same solution what will be it's osmotic pressure by keeping temperature constant

Answer 1

the osmotic pressure will be doubled i.e., 7.68 atm.

• osmotic pressure, π = iMRT where i = vant hoff factor, M = molecular concentration, R = universal gas constant, T = temperature.

• let π1 = 3.84 atm, M1 = 10/180 mol/L = 0.055 mol/L, M2 = 20/180 mol/L = 0.111 mol/L and π2 = changed osmotic pressure.

• As temperature is constant, T1 = T2   ⇒  π1 / i M1 R = π2 / i M2 R           ⇒ π1 / M1 = π2 / M2 ⇒ 3.84/0.055 = π2 / 0.111 ⇒ π2 = 7.68 atm