Chapter 5, Problem 5.103PAE

Interpretation Introduction

Interpretation:

To suggest a reason (a) why the given approach is attractive in aerospace engineering, (b) to determine the average molecular mass of air and (c) to determine the value of ${\text{R}}_{\text{speicfic}}$

Concept introduction:

Mole fraction is the number of moles present of an individual component. Mole fraction of gas X can be calculated as follows:${\text{X}}_{\text{x}}=\frac{{\text{n}}_{\text{X}}}{{\text{n}}_{\text{T}}}$

Here, ${\text{n}}_{\text{X}}$ is number of moles of gas X and ${\text{n}}_{\text{T}}$ is total number of moles of gases.

The ideal gas law is mathematically expressed as:$\text{PV}=\text{nRT}$

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

Given:$\text{PV}={\text{mR}}_{\text{specific}}\text{T}$

Mole fractions of oxygen and nitrogen gas:$\begin{array}{l}{\text{O}}_{\text{2}}=\text{0}\text{.21}\\ {\text{N}}_{\text{2}}=\text{0}\text{.79}\end{array}$