Chapter 6, Problem 6.23P

(a)

Interpretation Introduction

Interpretation:

Whether $\Delta H$ is less than (more negative), equal to, or greater than $\Delta E$ when an ideal gas is cooled at constant pressure is to be determined.

Concept introduction:

The internal energy of a process is the summation of the kinetic energy and potential energy associated with the process. In the case of a reaction, the change in internal energy $\left(\Delta E\right)$ is the difference in the energy of the product and reactant but at constant pressure the $P\Delta V$ work gets eliminated and the change in enthalpy $\left(\Delta H\right)$ is measured. The relationship $\Delta E$ and $\Delta H$ is as follows:

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

Here,

$\Delta E$ is the change in internal energy of the system.

$\Delta H$ is the change in enthalpy of the system.

$P$ is the external pressure.

$\Delta V$ is the change in the volume

(b)

Interpretation Introduction

Interpretation:

Whether $\Delta H$ is less than (more negative), equal to, or greater than $\Delta E$ when a gas mixture reacts exothermically at fixed volume is to be determined.

Concept introduction:

The internal energy of a process is the summation of the kinetic energy and potential energy associated with the process. In the case of a reaction, the change in internal energy $\left(\Delta E\right)$ is the difference in the energy of the product and reactant but at constant pressure the $P\Delta V$ work gets eliminated and the change in enthalpy $\left(\Delta H\right)$ is measured. The relationship $\Delta E$ and $\Delta H$ is as follows:

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

Here,

$\Delta E$ is the change in internal energy of the system.

$\Delta H$ is the change in enthalpy of the system.

$P$ is the external pressure.

$\Delta V$ is the change in the volume

(c)

Interpretation Introduction

Interpretation:

Whether $\Delta H$ is less than (more negative), equal to, or greater than $\Delta E$ when solid reacts exothermically to yield a mixture of gases in a container of variable volume is to be determined.

Concept introduction:

The internal energy of a process is the summation of the kinetic energy and potential energy associated with the process. In the case of a reaction, the change in internal energy $\left(\Delta E\right)$ is the difference in the energy of the product and reactant but at constant pressure the $P\Delta V$ work gets eliminated and the change in enthalpy $\left(\Delta H\right)$ is measured. The relationship $\Delta E$ and $\Delta H$ is as follows:

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

Here,

$\Delta E$ is the change in internal energy of the system.

$\Delta H$ is the change in enthalpy of the system.

$P$ is the external pressure.

$\Delta V$ is the change in the volume