Chapter 20, Problem 20.93P

(a)

Interpretation Introduction

Interpretation:

The given reaction has to be shown whether it is thermodynamically feasible or not.

Concept introduction:

Free energy (or) entropy change is the term that is used to explain the total energy content in a thermodynamic system that can be converted into work.  The free energy is represented by the letter G.  All spontaneous process is associated with the decrease of free energy in the system.  The equation given below helps us to calculate the change in free energy in a system.

  ${\text{ΔG}}^{\text{o}}\text{ = }\Delta {{\rm H}}^{\text{o}}\text{- T}\Delta {\text{S}}^{\text{o}}$

Where,

  ${\text{ΔG}}^{\text{o}}$ is the standard change in free energy of the system

  $\Delta {{\rm H}}^{\text{o}}$ is the standard change in enthalpy of the system

  $\text{T}$ is the absolute value of the temperature

  $\Delta {\text{S}}^{\text{o}}$ is the change in entropy in the system

(b)

Interpretation Introduction

Interpretation:

The given methanol formation reaction has to be shown that whether it is favored at low or at high temperatures.

Concept introduction:

Any natural process or a chemical reaction taking place in a laboratory can be classified into two categories, spontaneous or nonspontaneous. Spontaneous process occurs by itself, without the influence of external energy. In spontaneous process the free energy of the system decreases and entropy of the system increases. Nonspontaneous process requires an external influence for initiation. In nonspontaneous process the free energy of the system increases but entropy in the system decreases.

In thermodynamics a process is spontaneous if it is taking place by itself without the help of external energy.  All spontaneous process will have highly energetic initial state than the final state. This indicates that while the process occurs, there is a decrease in free energy of the system. The increase in randomness also favors the spontaneity of a process.

(c)

Interpretation Introduction

Interpretation:

For the given methanol oxidation reaction the ${\text{ΔG}}^{\text{o}}$ value has to calculate at ${100}^{o}C$.

Concept introduction:

Free energy (or) entropy change is the term that is used to explain the total energy content in a thermodynamic system that can be converted into work.  The free energy is represented by the letter G.  All spontaneous process is associated with the decrease of free energy in the system.  The equation given below helps us to calculate the change in free energy in a system.

  ${\text{ΔG}}^{\text{o}}\text{ = }\Delta {{\rm H}}^{\text{o}}\text{- T}\Delta {\text{S}}^{\text{o}}$

Where,

  ${\text{ΔG}}^{\text{o}}$ is the standard change in free energy of the system

  $\Delta {{\rm H}}^{\text{o}}$ is the standard change in enthalpy of the system

  $\text{T}$ is the absolute value of the temperature

  $\Delta {\text{S}}^{\text{o}}$ is the change in entropy in the system