The boiling point of 0.2 mol kg-1 solution of X in water is greater than equimolal solution of Y in water. Which one of the following statements is true in this case ?
Molecular mass of X is less than the molecular mass of Y.
Y is undergoing dissociation in water while X undergoes no change.
X is undergoing dissociation in water.
Molecular mass of X is greater than the molecular mass of Y.
As we learned in concept ID
Molality -
-
Vant Hoff factor for dissociation -
Where
is the no. of dissociated particles
degree of association
- wherein
The only factor among all the options that could make a difference is that X to undergo dissociation thereby making i>1 and therfore boiling higher boiling tempreture.
Option 1)
Molecular mass of X is less than the molecular mass of Y.
Incorrect option
Option 2)
Y is undergoing dissociation in water while X undergoes no change.
Incorrect option
Option 3)
X is undergoing dissociation in water.
Correct option
Option 4)
Molecular mass of X is greater than the molecular mass of Y.
Incorrect option