(The queston is from relative molecular mass and mole)

A solution of glycol containing 1.82g per litre has an osmotic pressure of 51.8cm of mercury at 10°C .What is the molecular weight of glycol?

(ans is 62.04)

:   w= 1.82g   V= 1L   π = 51.8 cm =518mm =0.68 atm.

  T= 10°C = 283K  R= 0.082 lit-atm mol/K  M = ?

Formula:   πV = wRT/M  [n=w/m]

Putting the value of parameter in given formula, the molecular weight of substance is 62.11.