Chapter 10, Problem 10.5P

Interpretation Introduction

(a)

Interpretation:

The density of the methane and nitrogen needs to be determined.

Concept introduction:

The ideal-gas equation (also called as ideal-gas law) gives a decent estimate of numerous gases under certain conditions. The ideal-gas law is displayed below:

$\begin{array}{l}\text{PV}=\text{nRT}\\ \text{or}\\ \text{n}=\frac{\text{PV}}{\text{RT}}\end{array}$

Here,

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

Interpretation Introduction

(b)

Interpretation:

The volume of the nitrogen required to displace all the methane from the tank should be calculated.

Concept introduction:

Density is defined as the ratio of Mass of a substance to its volume. A high-density liquid can displace a low-density liquid in a container as the high-density liquid moves down upon mixing it with a low-density liquidand the low-density liquid will move to the top and in this way high density liquid displaces the low-density liquid.

Interpretation Introduction

(c)

Interpretation:

The volume of the air needs to increase the oxygen concentration by 20% should be calculated.

Concept introduction:

In general, air consists of 79 mole% Nitrogen and 21 mole% Oxygen.

Interpretation Introduction

(d)

Interpretation:

The reason behind using nitrogen for purging instead of air should be explained.

Concept introduction:

Purging is the method of removing moisture content within the equipment to produce dry environment. Mostly the nitrogen is used for the purpose of purging and blanketing.