Chapter 5, Problem 5.15E

(a)

Interpretation Introduction

Interpretation:

The freezing point of a $5.00\%$ by mass aqueous acetic acid solution is $-1.72{}^{\text{o}}C$, molar mass of solute has to be calculated.

Concept Introduction:

Molar mass can be calculated by using following formula,

  $\begin{array}{l}\Delta {\text{T}}_{\text{f}}\text{=}{\text{ik}}_{\text{f}}m\\ \Delta {\text{T}}_{\text{f}}\text{=}{\text{ik}}_{\text{f}}\left(\frac{\frac{m_{solute}}{M_{solute}}}{kgsolvent}\right)\\ \\ \text{Where,}\\ \Delta {\text{T}}_{\text{f}}\text{-}Freezingpo\mathrm{int}depression\\ {\text{k}}_{\text{f}}\text{-}\text{freezing}\text{point}\text{molar constant}\text{of}\text{solvent}\end{array}$

(b)

Interpretation Introduction

Interpretation:

The freezing point depression associated with a $5.00\%$ by mass solution of acetic acid in benzene is $2.32{}^{\text{o}}C$, the experimental molar mass of solute in benzene has to be calculated.

Concept introduction:

Refer to part (a)