Chapter 19, Problem 87AE

(a)

Interpretation Introduction

To determine: The authenticity of the given statement, “The feasibility of manufacturing ${\text{NH}}_3$ from ${\text{N}}_2$ and ${\text{H}}_2$ depends entirely on the value of $\Delta H$ for the process”.

Solution: The given statement is true.

Explanation:

The balanced chemical equation for the given reaction is,

${\text{N}}_2\left(g\right)+3{\text{H}}_2\left(g\right)\to 2{\text{NH}}_3\left(g\right)$

The feasibility of the reaction is determined by the value of free energy change of the reaction. If the value of free energy change is negative then the given reaction is feasible and vice versa.

The reaction of manufacturing of ammonia involves the formation of two gaseous products from four gaseous reactants which results in the decrease in randomness of the system and also the entropy change. Therefore, the feasibility of the reaction entirely depends upon the value of enthalpy change according to the given formula,

$\Delta G^0=\Delta H^0-T\Delta S^0$

Where,

• $\Delta G^0$ is the standard free energy change of the reaction.
• $\Delta H^0$ is the standard enthalpy change of the reaction.
• $T$ is the temperature of the reaction.
• $\Delta S^0$ is the standard entropy change of the reaction.

Conclusion:

The given statement is true.

(b)

Interpretation Introduction

To determine: The authenticity of the given statement, “The reaction of $\text{Na}\left(s\right)$ with ${\text{Cl}}_2\left(g\right)$ to form $\text{NaCl}\left(s\right)$ is a spontaneous process”.

(c)

Interpretation Introduction

To determine: The authenticity of the given statement, “A spontaneous process can in principle be conducted reversibly”.

(d)

Interpretation Introduction

To determine: The authenticity of the given statement, “Spontaneous processes in general require that work be done to force them to proceed”.

(e)

Interpretation Introduction

To determine: The authenticity of the given statement, “Spontaneous processes are those that are exothermic and that lead to high degree of order in the system”.