Chapter 12, Problem 18PE

Interpretation Introduction

Interpretation:

The amount of stearic acid (in grams), required to add in the given amount of acetone to prepare a solution having given vapor pressure, is to be calculated.

Concept Introduction:

The Raoult’s law gives the relationship between the partial vapor pressure of solution and solvent. This law states that the partial pressure of the solvent in the solution $\left(P_1\right)$ is equivalent to the product of mole fraction of the solvent $\left({\chi }_1\right)$, and to the partial pressure of pure solvent $\left(P_1^{°}\right)$. It is expressed as follows:

$P_1={\chi }_1{P}_1^{°}$

Mole fraction of a component is defined as the ratio between the number of moles of that component and the sum of number of moles of all the components present in the mixture. The relationship between mole fraction $\left(\chi \right)$ and moles $\left(n\right)$ of component is as follows:

${\chi }_1=\frac{n_1}{n_1+n_2+\mathrm{....}}$