Chapter 18, Problem 5PS

(a)

Interpretation Introduction

Interpretation: It should be predicted that whether the given process that is Water vapour condenses as liquid water at $\text{0 }°\text{C}$ and $\text{1 atm}$ pressure results in increase in entropy of the system or not.

Concept introduction: The process is said to be spontaneous if the entropy change should increase and the value of change in free energy should be negative.

Entropy increases in the order $\text{solid < liquid < gas}$. In the gaseous state, the particles are more random. In solids, the particles have fixed positions and entropy is less. In liquids, there are constraints due to forces between the particles. The increase in entropy results in a spontaneous process.

Reactions that involve increased number of moles in a gaseous system results in increased entropy of the system.

(b)

Interpretation Introduction

Interpretation: It should be predicted that whether the given process that is exothermic reaction of $\text{Al}\left(\text{s}\right)$ and ${\text{Br}}_{\text{2}}\left(\text{l}\right)$ in formation of ${\text{Al}}_{\text{2}}{\text{Br}}_{\text{6}}\left(\text{s}\right)$ results in increase in entropy of the system or not.

Concept introduction: The process is said to be spontaneous if the entropy change should increase and the value of change in free energy should be negative.

Entropy increases in the order $\text{solid < liquid < gas}$. In the gaseous state, the particles are more random. In solids, the particles have fixed positions and entropy is less. In liquids, there are constraints due to forces between the particles. The increase in entropy results in a spontaneous process.

Reactions that involve increased number of moles in a gaseous system results in increased entropy of the system.

(c)

Interpretation Introduction

Interpretation: It should be predicted that whether the given process that is endothermic decomposition of solid ${\text{CaCO}}_{\text{3}}$ results in increase in entropy of the system or not.

Concept introduction: The process is said to be spontaneous if the entropy change should increase and the value of change in free energy should be negative.

Entropy increases in the order $\text{solid < liquid < gas}$. In the gaseous state, the particles are more random. In solids, the particles have fixed positions and entropy is less. In liquids, there are constraints due to forces between the particles. The increase in entropy results in a spontaneous process.

Reactions that involve increased number of moles in a gaseous system results in increased entropy of the system.

(d)

Interpretation Introduction

Interpretation: It should be predicted that whether the given process that is decomposition of one mole of $\text{AgCl}\left(\text{s}\right)$ to form $\text{1}\text{.0 mole}$ of $\text{Ag}\left(\text{s}\right)$ and $\text{0}\text{.5 mol}$ of ${\text{Cl}}_{\text{2}}\left(\text{g}\right)$ results in increase in entropy of the system or not.

Concept introduction: The process is said to be spontaneous if the entropy change should increase and the value of change in free energy should be negative.

Entropy increases in the order $\text{solid < liquid < gas}$. In the gaseous state, the particles are more random. In solids, the particles have fixed positions and entropy is less. In liquids, there are constraints due to forces between the particles. The increase in entropy results in a spontaneous process.

Reactions that involve increased number of moles in a gaseous system results in increased entropy of the system.