Concentrations of ions in 0.1M aluminium sulphate [Al2(SO4)3] is ‌=0.1[2×(Al3+)‌ ions ‌+3×(SO42−)‌ ions ‌] ‌=0.1[2×1+3×1]=0.1×5=05M Concentrations of ions in 0.1M potassium nitrate (KCl) is =0.1(1. mole of K++1 mole of Cl−) =0.1×2=0.2M Concentration of ions in 0.1M magnesium chloride (MgCl2) is =0.1(1. mole of Mg2++2 moles of Cl−) =0.1×3=0.3M Concentration of ions in 0.1M barium chloride (BaCl2) is =0.1(1. mole of Ba2++2 moles of Cl−) =0.1×3=0.3M ∴ Order of concentration is 0.1MAl2(SO4)3>0.1M‌KCl>0.1MgCl2 ≈0.1MBaCl2 ∵ Osmotic pressure is colligative property and, it depends on concentration of ions. ∴ Order of osmotic pressure is ‌0.1M(Al2SO4)3>0.1M‌KCl>0.1MMgCl2 >0.1MBaCl2