Question

QUESTION 13

What is the boiling point of a 0.50 m aqueous solution of Al(NO 3) 3?
(The boiling point elevation constant for water is 0.512 °C/m.)
O a. 100.51 °c O b. 101.02 °c O C. 102.05 °C 0 d. 106.60 °C

Answer 1

b. 101.02°C

Step-by-step explanation:

The elevation of boiling point in a solvent due the addition of a solute is a colligative property called Boiling point Elevation. The formula is:

ΔT = Kb*m*i

Where ΔT is change in boiling point

Kb is boilinig point elevation constant = 0.512°C/m for water

m is molality of the solution = 0.50m

And i is Van't Hoff Factor (4 for the Al(NO₃)₃ because its disolution produce 4 ions)

Replacing:

ΔT = 0.512°C/m*0.50m*4

ΔT = 1.02°C

As the boiling point of pure water is 100°C and the increasing is of 1.02°C, boiling point of the solution is:

101.02°C

Right option is:

b. 101.02°C