A solution of urea contains 8.6 gm/litre (mol. Wt. 60.0). It is isotonic with a 5% (W/W) solution of a non-volatile solute having density 1 g/cc. The molecular weight of the solute will be
Isotonic solutions have same osmotic pressure
As Osmotic pressure = C R T
⇒ C1=C2
⇒ n1V1=n2V2
5% W/W solution means 100g of solution contains 5 g of solute
∴ 8.6601=5M1001000
⇒ M=5×60×108.6=348.8