Question

A solution containing 10 g glucose has osmotic pressure 3.84 atm. If 10 g more glucose is added to the same solution, what will be its osmotic pressure? (Temperature remains constant)

Answer 1

Given: Mass of glucose = W₁ - 10g

Mass of more glucose added = W₂ = 10g

Initial osmotic pressure = π₁ = 3.84 atm

Final osmotic pressure = π₂ = ?

Total mass of glucose in final solution = W₁ + W₂

W' = 10 + 10 = 20g

`π_1 = W_1/M xx (RT)/V`

`π_2 = (W')/M xx (RT)/V`

`∴ π_1/π_2 = ((W'RT)/(M xx V))/((W_1RT)/(M xx V)) = (W')/W_1`

`∴ π_2 = π_1 xx (W')/W_1 = 3.84 xx 20/10 = 7.68  "atm"`

∴ The osmotic pressure of the solution = 7.68 atm