3. 7moles of Ba(NO3)2 is dissolved in 75kg of distilled water. What is the boiling point of this solution? Hint: Find molality first.

100.14°C

Explanation:

The boling point elevation is a colligative property that describes the increasing in boiling point of a solution regard to the boiling point of the pure solvent. The equation is:

ΔT = Kf*m*i

Where ΔT is boiling point elevation

Kf is boiling point elevation (0.51°C/m for water)

m is molality of the solution (7moles Ba(NO3)2 / 75kg = 0.09333m

i is Van't Hoff factor = 3 for Ba(NO3)2 (Because its dissolution produce 3 ions = Ba²⁺ and 2 NO₃⁻

Replacing:

ΔT = 0.51°C/m*0.09333m*3

ΔT = 0.14°C is the boiling point elevation

As the boiling point of water is 100°C, the boiling point of the solution is:

100°C + 0.14°C =