Chapter 20, Problem 20.34P

(a)

Interpretation Introduction

Interpretation:

For the given reaction, the entropy sign and ${\text{ΔS}}_{\text{rxn}}^{\text{o}}$ value has to be predicted.

    $3N{O}_2\left(g\right)+H_{2}O\left(l\right)\stackrel{}{\to }2HN{O}_3\left(l\right)+NO\left(g\right)$

Concept introduction:

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.

Entropy$\left(S\right)$: It is used to describe the disorder. It is the amount of arrangements possible in a system at a particular state.

If the disorder increases in a system, then $\Delta S>0$

If the disorder decreases in a system, then $\Delta S<0$

If the disorder equal in a system, then $\Delta S=0$

Entropy change: The sign of ${\text{ΔS}}^{\text{o}}$ for a reaction is determined by using the following rules:

• When a molecule is broken down and gives two or more smaller molecules.
• When the moles of gas is increases (by the breaking of molecules)
• Solid changes to liquid or gas state or liquid state changes to gas state.

(b)

Interpretation Introduction

Interpretation:

For the given reaction, the entropy sign and ${\text{ΔS}}_{\text{rxn}}^{\text{o}}$ value has to be predicted.

Concept introduction:

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.

Entropy$\left(S\right)$: It is used to describe the disorder. It is the amount of arrangements possible in a system at a particular state.

If the disorder increases in a system, then $\Delta S>0$

If the disorder decreases in a system, then $\Delta S<0$

If the disorder equal in a system, then $\Delta S=0$

Entropy change: The sign of ${\text{ΔS}}^{\text{o}}$ for a reaction is determined by using the following rules:

• When a molecule is broken down and gives two or more smaller molecules.
• When the moles of gas is increases (by the breaking of molecules)
• Solid changes to liquid or gas state or liquid state changes to gas state.

(c)

Interpretation Introduction

Interpretation:

For the given each reactions, the entropy sign and ${\text{ΔS}}_{\text{rxn}}^{\text{o}}$ value has to be predicted.

Concept introduction:

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.

Entropy$\left(S\right)$: It is used to describe the disorder. It is the amount of arrangements possible in a system at a particular state.

If the disorder increases in a system, then $\Delta S>0$

If the disorder decreases in a system, then $\Delta S<0$

If the disorder equal in a system, then $\Delta S=0$

Entropy change: The sign of ${\text{ΔS}}^{\text{o}}$ for a reaction is determined by using the following rules:

• When a molecule is broken down and gives two or more smaller molecules.
• When the moles of gas is increases (by the breaking of molecules)
• Solid changes to liquid or gas state or liquid state changes to gas state.