Chapter 2, Problem 2D.1E

Interpretation Introduction

Interpretation:

The change in enthalpy of the parcel of air has to be calculated.

Concept Introduction:

According to First law of Thermodynamics, work done is given by,

$w=-P\Delta V$

Where,

$\begin{array}{l}P=\text{ pressu}re\\ \\ \Delta V=\text{ change in volume}\end{array}$

The heat content of the system is represented by ‘H’ and it is the sum of internal energy ‘U’ and product of volume and pressure,

$H=E+PV$

$\Delta H$ refers to change in enthalpy of the system and $\Delta U$ refers to change in internal energy of the system.  Both are related as,

$\Delta H=\Delta U+P\Delta V$