Chapter 1, Problem 1.20NP

(a)

Interpretation Introduction

Interpretation: The total pressure at 8.5 km needs to be determined if mean molecular mass is 28.9 g/mol and temperature is 300 K. Also, at sea level the mole fraction of nitrogen and helium gas is $\text{ 0}\text{.78084}$ and $\text{ 0}\text{.00000524}$ respectively.

Concept Introduction: The partial pressure of the component of air above the sea level in the atmosphere of the earth can be calculated as follows:

  $P_i=P_i^o{e}^{-M_{i}gz/RT}$

Here, $P_i$ is partial pressure at z height, $P_i^o$ is partial pressure of component i at the sea level, g is acceleration due to gravity, R is Universal gas constant, M is molar mass of the gas and T is temperature.

(b)

Interpretation Introduction

Interpretation: The value of ratio of mole fraction of nitrogen and helium gas at 8.5 km needs to be determined in the absence of the turbulent mixing.

Concept Introduction: The partial pressure of the component of air above the sea level in the atmosphere of the earth can be calculated as follows:

  $P_i=P_i^o{e}^{-M_{i}gz/RT}$

Here, $P_i$ is partial pressure at z height, $P_i^o$ is partial pressure of component i at the sea level, g is acceleration due to gravity, R is Universal gas constant, M is molar mass of the gas and T is temperature.