Question

Which among the following is a property of Boiling Point Elevation?
A.Additive Property
B.Constitutive Property
C.Colligative Property
D.Partly additive and partly constitutive

Answer 1

Hint: Boiling Point Elevation means increase in boiling point of the solvent after addition of solute to it. It depends on the solute to solvent ratio. The Greater the amount of non-volatile solute gets added to the solution, the greater will be the elevation in boiling point.

Complete step by step answer:
As discussed above, boiling point elevation refers to an increase in boiling point of the solvent in addition to solute which occurs whenever in pure solvent any non volatile solute is added. For example, adding salt to water. Now, let’s see what Additive Property, Constitutive Property and Colligative Property means.
Additive Property- An additive property refers to the property which suffers a change when mass, volume and size.
Constitutive Property- These are the properties that depend upon the constitutional arrangement of atoms within the molecules.
Colligative Property- It is the ratio of number of solute particles to number of solvent particles in a solution. It does not depend upon the nature of chemical species present.
 As we know, Boiling Point Elevation depends on solute to solvent ratio. Also, as studied above, Colligative properties depend upon the ratio of number of solute particles to number of solvent molecules in a solution and does not depend upon the nature of chemical species present.
Hence, after relating to above points, it is understood that options A, B, D are incorrect.
So, the correct answer is Colligative Property i.e. option C.

Note:
 It depends only on the number of particles like ions or molecules of the solute in a definite amount of the solvent but not on the nature of the solute. Moreover, boiling point elevation constant is equal to the elevation in boiling point when one mol of solute is dissolved in one kilogram of solvent. It is also called ebullioscopic constant.