question_answer

Direction (11-15): The four colligative properties of the dilute solutions help in calculating the molecular mass of the solute which is often called observed molecular mass. It may be same as the theoretical molecular mass (calculated from the molecular formula) if the solute behaves normally in solution. In case, it undergoes association or dissociation, the observed molar mass gives different results. The nature of the solute in solution is expressed in terms of Van't Hoff factor (i) which may be 1 (if the solute behaves normally), less than 1 (if the solute associates) and more than 1 (if the solute dissociates). The extent of association or dissociation is represented by a which is :

\[\alpha =\frac{i-1}{\left( 1/n-1 \right)}\]   or         \[\frac{i-1}{n-1}\] (for association)              (for dissociation)

The Van't Hoff factor for dilute solution of glucose is :

A) zero                              

B) 1

C) \[1\centerdot 5\]

D) \[2\centerdot 0.\]