Chapter 13, Problem 13.69P

(a)

Interpretation Introduction

Interpretation:

The aqueous solution of ethanol is to be prepared.

Concept introduction:

Molality is the measure of the concentration of solute in the solution. It is the amount of solute that is dissolved in one kilogram of the solvent. It is represented by $\text{m}$ and its unit is moles per kilograms. The solute is the substance that is present in a smaller amount and solvent is the substance that is present in a larger amount.

The formula to calculate the molality of the solution is as follows:

$\text{Molality}=\frac{\text{amount}\left(\text{mol}\right)\text{of}\text{solute}}{\text{mass}\left(\text{kg}\right)\text{of}\text{}\text{solvent}}$ (1)

(b)

Interpretation Introduction

Interpretation:

The aqueous solution of $\text{HCl}$ is to be prepared.

Concept introduction:

Mass percent is defined as the mass of a component divided by the total mass of the mixture, multiplied by 100.

The formula to calculate the mass percent is as follows:

$\text{Mass}\text{percent}=\left(\frac{\text{mass}\text{of}\text{solute}}{\text{mass}\text{of}\text{solution}}\right)\left(100\right)$ (7)