Chapter 18.3, Problem 2RC

(a)

Interpretation Introduction

Interpretation:

The change in entropy in the given vaporization process has to be explained.

Concept Introduction:

Entropy is a thermodynamic quantity, which is the measure of randomness in a system.  The term entropy is useful in explaining the spontaneity of a process.  For all spontaneous process in an isolated system there will be an increase in entropy.  Let us consider the example of diffusion of gas molecule to understand the concept of entropy.  When a perfume bottle is opened the fragrance is immediately spread into the surroundings.  Inside the bottle the gas molecules are close to each other and entropy is less.  Once the bottle is opened the gas molecules escapes into the surroundings and have more disorderly arrangements.

Entropy is the measure of randomness in the system.   Standard entropy change in a reaction is the difference in entropy of the products and reactants.  ${\text{(ΔS}}^{\text{°}}{}_{\text{rxn}}\text{)}$  can be calculated by the following equation.

  ${\text{ΔS}}^{\text{°}}{}_{\text{rxn}}{\text{ = S}}^{\text{°}}{}_{\text{Products}}-{\text{ S}}^{\text{°}}{}_{\text{reactants}}$

Where,

  ${\text{S}}^{\text{°}}{}_{\text{reactants}}$ is the standard entropy of the reactants

  ${\text{S}}^{\text{°}}{}_{\text{Products}}$ is the standard entropy of the products

Standard entropy change in a reaction and entropy change in the system are same.

(b)

Interpretation Introduction

Interpretation:

The change in entropy in the given melting process has to be explained.

Concept Introduction:

Entropy is a thermodynamic quantity, which is the measure of randomness in a system.  The term entropy is useful in explaining the spontaneity of a process.  For all spontaneous process in an isolated system there will be an increase in entropy.  Let us consider the example of diffusion of gas molecule to understand the concept of entropy.  When a perfume bottle is opened the fragrance is immediately spread into the surroundings.  Inside the bottle the gas molecules are close to each other and entropy is less.  Once the bottle is opened the gas molecules escapes into the surroundings and have more disorderly arrangements.

Entropy is the measure of randomness in the system.   Standard entropy change in a reaction is the difference in entropy of the products and reactants.  ${\text{(ΔS}}^{\text{°}}{}_{\text{rxn}}\text{)}$  can be calculated by the following equation.

  ${\text{ΔS}}^{\text{°}}{}_{\text{rxn}}{\text{ = S}}^{\text{°}}{}_{\text{Products}}-{\text{ S}}^{\text{°}}{}_{\text{reactants}}$

Where,

  ${\text{S}}^{\text{°}}{}_{\text{reactants}}$ is the standard entropy of the reactants

    ${\text{S}}^{\text{°}}{}_{\text{Products}}$ is the standard entropy of the products

Standard entropy change in a reaction and entropy change in the system are same.

(c)

Interpretation Introduction

Interpretation:

The change in entropy for the given sublimating process has to be explained.

Concept Information:

Entropy is a thermodynamic quantity, which is the measure of randomness in a system.  The term entropy is useful in explaining the spontaneity of a process.  For all spontaneous process in an isolated system there will be an increase in entropy.  Let us consider the example of diffusion of gas molecule to understand the concept of entropy.  When a perfume bottle is opened the fragrance is immediately spread into the surroundings.  Inside the bottle the gas molecules are close to each other and entropy is less.  Once the bottle is opened the gas molecules escapes into the surroundings and have more disorderly arrangements.

Entropy is the measure of randomness in the system.   Standard entropy change in a reaction is the difference in entropy of the products and reactants.  ${\text{(ΔS}}^{\text{°}}{}_{\text{rxn}}\text{)}$  can be calculated by the following equation.

  ${\text{ΔS}}^{\text{°}}{}_{\text{rxn}}{\text{ = S}}^{\text{°}}{}_{\text{Products}}-{\text{ S}}^{\text{°}}{}_{\text{reactants}}$

Where,

  ${\text{S}}^{\text{°}}{}_{\text{reactants}}$ is the standard entropy of the reactants

  ${\text{S}}^{\text{°}}{}_{\text{Products}}$ is the standard entropy of the products

Standard entropy change in a reaction and entropy change in the system are same.

(d)

Interpretation Introduction

Interpretation:

The change in entropy in the given sublimating process has to be explained.

Concept Introduction:

Entropy is a thermodynamic quantity, which is the measure of randomness in a system.  The term entropy is useful in explaining the spontaneity of a process.  For all spontaneous process in an isolated system there will be an increase in entropy.  Let us consider the example of diffusion of gas molecule to understand the concept of entropy.  When a perfume bottle is opened the fragrance is immediately spread into the surroundings.  Inside the bottle the gas molecules are close to each other and entropy is less.  Once the bottle is opened the gas molecules escapes into the surroundings and have more disorderly arrangements.

Entropy is the measure of randomness in the system.   Standard entropy change in a reaction is the difference in entropy of the products and reactants.  ${\text{(ΔS}}^{\text{°}}{}_{\text{rxn}}\text{)}$  can be calculated by the following equation.

  ${\text{ΔS}}^{\text{°}}{}_{\text{rxn}}{\text{ = S}}^{\text{°}}{}_{\text{Products}}-{\text{ S}}^{\text{°}}{}_{\text{reactants}}$

Where,

  ${\text{S}}^{\text{°}}{}_{\text{reactants}}$ is the standard entropy of the reactants

  ${\text{S}}^{\text{°}}{}_{\text{Products}}$ is the standard entropy of the products

Standard entropy change in a reaction and entropy change in the system are same.