From molarity equation

M₁V₁ + M₂V₂ = MV

$$ \Rightarrow $$ 1× 2.5 + 0.5 × 3 = M × 5.5

$$ \Rightarrow $$ M = $${4 \over {5.5}}$$ = 0.73M

For dilute solution, the van’t Hoff equation is

$$\pi = {n \over V}RT$$

$$ \Rightarrow $$ $$\pi V = nRT$$

$$ \Rightarrow $$ $$\pi V = {{{m_2}} \over M}RT$$

$$ \Rightarrow $$ $${M_2} = \left( {{{{m_2}} \over V}} \right){{RT} \over \pi }$$

These two components A and B follows the condition of Raoult’s law if the force of attraction between A and B is equal to the force of attraction between A and A or B and B.

The osmotic pressure of sea water is 25 atm at 15°C. When pressure greater than 26 atm is applied on sea water separated by a rigid semipermeable membrane. Pure water is obtained. This is also called desalination of sea water.