Question

A substance x (molar mass 94) associates as 2x gives x2 when dissolved in CCl4. If 10 g of x is dissolved in in 2kg of ccl4, teh freezing point is lowered by 1.08 degree C. Calculate degree of association of x

Answer 1

Answer:

we know by the formula in Raoult's Law

Given : Weight of Solute = 10 gram

Weight of Solvent = 2000 gram

Theoretical Molecular mass = 94

Depression in Freezing point = 1.08

Cryoscopic constant= 31.8 C

del Tf= Kf * weight of solute * Observed molecular mass of Solvent CCl4

                  weight of solvent* Observed molecular mass of solute x    

   del Tf= 31.8 * 10* 1000

               2000*1.08

degree of association= Theoretical mol mass/Observed Molecular Mass

94/147.22

0.639

 

Explanation: