Chapter 10.5, Problem 1CP

Interpretation Introduction

Interpretation:

The partial pressure of helium is to be calculated.

Concept introduction:

The mole fraction of an individual gas, for a combination of gases, is the ratio of the moles of the individual gas to the total number of moles of the mixture.

${\chi }_i=\frac{n_i}{n_{\text{total}}}$

Here, ${\chi }_i$ is the mole fraction, $n_i$ is the mole fraction of an individual gas, and $n_{\text{total}}$ is the total number of moles.

Also, the mole fraction of an individual gas, for a combination of gases, can be calculated from the ratio of the partial pressure of the individual gas to the total pressure of the combination.

${\chi }_i=\frac{P_i}{P_{\text{total}}}$

Here, ${\chi }_i$ is the mole fraction, $P_i$ is the partial pressure of individual gas, and $P_{\text{total}}$ is the total pressure.

The ideal gas equation elaborates the physical properties of gases by linking the pressure, volume, temperature, and number of moles with each other with the help of four gas laws. This can be shown by:

$P=\frac{nRT}{V}$

Here, $n$ is the number of moles, $R$ is the gas constant, $T$ is the temperature, $V$ is the volume, and $P$ is the pressure.

Gas constant having the values:

$\begin{array}{c}\text{R = 8}\text{.314 J/K mole}\\ \text{ = 0}\text{.08206 L atm/K mole}\\ \text{ = 1}\text{.98 cal /K mole}\end{array}$