A solution of citric acid C6H8O7 in 50 g of acetic acid has a boiling point elevation of 1.76 K. If Kb for acetic acid is 3.07 K kg mol-1, what is the molality of solution? - Chemistry

Exercise | Q 11 | Page 46

A solution of citric acid C6H8O7 in 50 g of acetic acid has a boiling point elevation of 1.76 K. If Kb for acetic acid is 3.07 K kg mol-1, what is the molality of solution?

Solution:

Given: Boiling point elevation =ΔT_b = 1.76 K

K_b of acetic acid = 3.07 K kg mol^-1

Mass of acetic acid = 50 g

To find: Molality of the solution

Formula: ΔT_b =  K_b m

Calculation: Using formula and rearranging, we get,

${\displaystyle \text{m}=\frac{△{\text{T}}_{\text{b}}}{{\text{K}}_{\text{b}}}=\frac{1.76\text{K}}{3.07{\text{K kg mol}}^{-1}}=0.573 {\text{mol kg}}^{-1}}$ = 0.573 m

The molality of the solution is 0.573 m.