Question

For a 5% solution of urea calculate the osmotic pressure at 300K

Answer 1

Answer:

Explanation:

R=0.082lit atmK−1

π=CRT

π=0.1×0.082×300

π=2.46 atm.

Answer 2

The osmotic pressure of 5% solution of urea at 300 K is 20.52 atm.

Explanation:

The osmotic pressure is given by the formula:

p = i × C × R × T

Where,

i = Van’t-Hoff factor = 1 (for non-electrolyte solution)

C = Concentration of solute

R = Gas constant = 0.082 L.atm/mol.K

T = Temperature

5% of urea = 5 g of urea in 100 ml of solution

Mole = (Given weight)/(Molecular weight)

On substituting the values, we get,

Moles = 5/60 = 0.083 mol

Now, the concentration of urea is given by the formula:

Molarity = (Moles of urea)/(Volume of solution) × 1000

Molarity = 0.083/100 × 1000

Molarity = 0.83 M

Now, the osmotic pressure is:

p = 1 × 0.83 × 0.082 × 300

∴ p = 20.418 atm