The O.P. (Osmotic Pressure) of equimolar solution of Urea, BaCl2 and AlCl3, will be in the order:
(a) AlCl3 > BaCl2 > Urea (b) BaCl2 > AlCl3 > Urea (c) Urea > BaCl2 > AlCl3 (d) BaCl2 > Urea > AlCl3
Answer: (a) The particle come of AlCl3 solution will be maximum due to ionisation less in BaCl2 and minimum in urea.
AlCl3 → Al3+ + 3Cl- = 4
BaCl2 → Ba2+ + 2Cl- = 3
More the number of particles in solution more is the osmotic pressure a colligative properties.