Chapter 1, Problem 1.19P

(a)

Interpretation Introduction

Interpretation:

Concentration of Helium in air is given as $5.24\text{ ppm}$ and number of moles of Helium in air at $25.00°C$ has to be calculated using ideal gas law.

Concept Introduction:

Ideal gas equation relates concentration of a gaseous substance with pressure and temperature.  The equation representing the relation is given as,

$PV\text{ = nRT}$

Where,

$\begin{array}{l}P=\text{ Pressure}\\ \text{V}\text{= Volume}\\ \text{n}\text{= Number of moles of the gaseous substance}\\ \text{T}\text{= Temperature}\\ \text{R}\text{= Universal gas constant}\end{array}$

Parts Per Million refers to a term that expresses concentration of certain substance in a mixture of substances.   It is denoted as ppm.  It is represented as,

$ppm\text{ = }\frac{mass\text{ of substance}}{mass\text{ of sample}}\times {10}^6$

In solution concentrations, $1\text{ ppm}$ is equivalent to $1\mu \text{g/mL or 1 mg/L}\text{.}$

(b)

Interpretation Introduction

Interpretation:

Molar concentration of Argon, Krypton, Xenon in air at $25.00°C$ and $1\text{ bar}$ has to be calculated.

Concept Introduction:

Ideal gas equation relates concentration of a gaseous substance with pressure and temperature.  The equation representing the relation is given as,

$PV\text{ = nRT}$

Where,

$\begin{array}{l}P=\text{ Pressure}\\ \text{V}\text{= Volume}\\ \text{n}\text{= Number of moles of the gaseous substance}\\ \text{T}\text{= Temperature}\\ \text{R}\text{= Universal gas constant}\end{array}$

Molarity, also formal concentration is one of the parameters used to express concentration of a solution.  It is defined as the number of moles of the solute dissolved per liter of the solution.  It is expressed as,

$\text{Molarity = }\frac{number\text{ of }molesof\text{ solute}}{volume\text{ of solution in L}}$

Parts Per Million refers to a term that expresses concentration of certain substance in a mixture of substances.   It is denoted as ppm.  It is represented as,

$ppm\text{ = }\frac{mass\text{ of substance}}{mass\text{ of sample}}\times {10}^6$

In solution concentrations, $1\text{ ppm}$ is equivalent to $1\mu \text{g/mL or 1 mg/L}\text{.}$

Parts Per Billion refers to a term that expresses concentration of certain substance in a mixture of substances.   It is denoted as ppb.  It is represented as,

$ppb\text{ = }\frac{mass\text{ of substance}}{mass\text{ of sample}}\times {10}^9$

In solution concentrations, $1\text{ ppb}$ is equivalent to $1\text{ ng/mL or 1 }\mu \text{g/L}\text{.}$

Volume percent is one of parameters used to express concentration of a solution and it is defined as percentage of volume of the solute present with respect to volume of the solution.  It is expressed as,

$\text{Volume percent of a solute = }\frac{\text{volume of solute}}{\text{volume of solution}}\times \text{ 100\%}$