The osmotic pressure is calculated as: π=iCRT For 5.0M urea, π=1×5×R×340 =1700R For 1.5MA2B3 type, π=4.1×1.5×R×300 =1800R For 3MAB type, π=1.6×3×R×300 =1440R For 2.5MAB2 type, π=2.5×2.5×R×330 =2062R Therefore, highest osmotic pressure is shown by the sample 2.5MAB2 type.