Chapter 12, Problem 12.139QP

Interpretation Introduction

Interpretation:

Aqueous acetic acid of molality $0.0830\text{ m}$ has freezing point $-0.159°C.$ acetic acid undergoes partial dissociation forming acetate ion and proton $(H^{+})$.  Percentage of acetic acid molecules that are dissociated has to be calculated.

Concept Introduction:

Depression in freezing point is the phenomenon of lowering of freezing point of a substance, which is considered as solvent, by adding a non-volatile solute.   It is expresses as –

$\Delta T_f=K_f\times m$

Where,

$\begin{array}{l}\Delta T_f\text{ = depression in freezing point}\\ {\text{K}}_f\text{ = cryoscopic constant}\\ \text{m = molality of the solute}\end{array}$