Chapter 8, Problem 51P

Interpretation Introduction

(a)

Interpretation:

The weight/volume percent concentration that contains $160\text{ mg}$ of acetaminophen in $\text{5 mL}$ is to be calculated.

Concept introduction:

Several concentration units may be used to express the concentration. It is often useful to express the concentration in terms of percentage. This can be expressed as the amount of solute in grams dissolved in $100\text{ mL}$ of solution that is termed as weight by volume percentage. The other way is to express the number of milliliters of solute per $100\text{ mL}$ of the solution.

The formula to calculate the weight/volume percent is as follows:

  $\text{Weight/volume percent}\left(\frac{\text{m}}{\text{v}}\right)\%=\frac{\text{Mass of solute}\left(\text{g}\right)}{\text{Volume of solution}\left(\text{mL}\right)}\times 100\%$

The conversion factor to convert milligrams into grams is as follows:

  $1\text{ mg}={\text{10}}^{-3}\text{ g}$

Interpretation Introduction

(b)

Interpretation:

The amount of acetaminophen present in $4\text{ fl oz}$ bottle is to be calculated in grams.

Concept introduction:

Several concentration units may be used to express the concentration. It is often useful to express the concentration in terms of percentage. This can be expressed as the amount of solute in grams dissolved in $100\text{ mL}$ of solution that is termed as weight by volume percentage. The other way is to express as number of milliliters of solute per $100\text{ mL}$ of the solution.

The conversion factor to fluid ounce into grams is as follows:

  $1\text{ fl oz}=29.57\text{ g}$

To convert one system of unit to another the conversion factors are written such that the unwanted units lie in the denominator and thus are cancelled out.