Chapter 18, Problem 18.99SP

Interpretation Introduction

(a)

Interpretation:

Whether synthesis of ${\text{C}}_6{\text{H}}_6\left(l\right)$ from its constituent elements is thermodynamically feasible or not should be determined.

Concept introduction:

Standard free-energy of substance formation use to define free-energy change for formation of $1\text{}\text{mol}$ of substance in its standard state. The reactant must be in its maximum stable form of constituent elements. It is denoted by $\Delta G{°}_{\text{f}}$. The general expression for $\Delta G{°}_{\text{f}}$ is as follows:

$\Delta G°=\Delta G{°}_{\text{f}}\left(\text{product}\right)-\Delta G{°}_{\text{f}}\left(\text{reactant}\right)$

The relationship between $\Delta H$ and $\Delta S$ is as follows:

$\Delta G=\Delta H-T\Delta S$

Where,

• $\Delta G$ is free energy change.
• $\Delta H$ is enthalpy change.
• $T$ is temperature.
• $\Delta S$ is change in entropy.

The entropy criteria for spontaneous change at constant $T$ and $P$ can also be stated with respect to free energy change as follows:

(1) When $\Delta G<0$, reaction is spontaneous.

(2) When $\Delta G>0$, reaction is nonspontaneous.

(3) When $\Delta G=0$, reaction is at equilibrium.

Interpretation Introduction

(b)

Interpretation:

Whether synthesis of $\text{NO}\left(g\right)$ from its constituent elements is thermodynamically feasible or not should be determined.

Concept introduction:

Standard free-energy of substance formation use to define free-energy change for formation of $1\text{}\text{mol}$ of substance in its standard state. The reactant must be in its maximum stable form of constituent elements. It is denoted by $\Delta G{°}_{\text{f}}$. The general expression for $\Delta G{°}_{\text{f}}$ is as follows:

$\Delta G°=\Delta G{°}_{\text{f}}\left(\text{product}\right)-\Delta G{°}_{\text{f}}\left(\text{reactant}\right)$

The relationship between $\Delta H$ and $\Delta S$ is as follows:

$\Delta G=\Delta H-T\Delta S$

Where,

• $\Delta G$ is free energy change.
• $\Delta H$ is enthalpy change.
• $T$ is temperature.
• $\Delta S$ is change in entropy.

The entropy criteria for spontaneous change at constant $T$ and $P$ can also be stated with respect to free energy change as follows:

(1) When $\Delta G<0$, reaction is spontaneous.

(2) When $\Delta G>0$, reaction is nonspontaneous.

(3) When $\Delta G=0$, reaction is at equilibrium.

Interpretation Introduction

(c)

Interpretation:

Whether synthesis of ${\text{PH}}_3\left(g\right)$ from its constituent elements is thermodynamically feasible or not should be determined.

Concept introduction:

Standard free-energy of substance formation use to define free-energy change for formation of $1\text{}\text{mol}$ of substance in its standard state. The reactant must be in its maximum stable form of constituent elements. It is denoted by $\Delta G{°}_{\text{f}}$. The general expression for $\Delta G{°}_{\text{f}}$ is as follows:

$\Delta G°=\Delta G{°}_{\text{f}}\left(\text{product}\right)-\Delta G{°}_{\text{f}}\left(\text{reactant}\right)$

The relationship between $\Delta H$ and $\Delta S$ is as follows:

$\Delta G=\Delta H-T\Delta S$

Where,

• $\Delta G$ is free energy change.
• $\Delta H$ is enthalpy change.
• $T$ is temperature.
• $\Delta S$ is change in entropy.

The entropy criteria for spontaneous change at constant $T$ and $P$ can also be stated with respect to free energy change as follows:

(1) When $\Delta G<0$, reaction is a spontaneous.

(2) When $\Delta G>0$, reaction is nonspontaneous.

(3) When $\Delta G=0$, reaction is at equilibrium.

d)

Interpretation Introduction

Interpretation:

Whether synthesis of $\text{FeO}\left(g\right)$ from its constituent elements is thermodynamically feasible or not should be determined.

Concept introduction:

Standard free-energy of substance formation use to define free-energy change for formation of $1\text{}\text{mol}$ of substance in its standard state. The reactant must be in its maximum stable form of constituent elements. It is denoted by $\Delta G{°}_{\text{f}}$. The general expression for $\Delta G{°}_{\text{f}}$ is as follows:

$\Delta G°=\Delta G{°}_{\text{f}}\left(\text{product}\right)-\Delta G{°}_{\text{f}}\left(\text{reactant}\right)$

The relationship between $\Delta H$ and $\Delta S$ is as follows:

$\Delta G=\Delta H-T\Delta S$

Where,

• $\Delta G$ is free energy change.
• $\Delta H$ is enthalpy change.
• $T$ is temperature.
• $\Delta S$ is change in entropy.

The entropy criteria for spontaneous change at constant $T$ and $P$ can also be stated with respect to free energy change as follows:

(1) When $\Delta G<0$, reaction is a spontaneous.

(2) When $\Delta G>0$, reaction is nonspontaneous.

(3) When $\Delta G=0$, reaction is at equilibrium.