Chapter 20, Problem 20.4P

(a)

Interpretation Introduction

Interpretation:

Using the given idea, the explanation for the given statement has to be given that is why suffocation occurs when all the air near you has moved to the other side of the room.

Concept introduction:

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. ${\text{ΔS}}_{\text{univ}}={\text{ΔS}}_{\text{sys}}+{\text{ΔS}}_{\text{surr}}.$

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. Entropy is represented by the letter ‘S’.  It is a state function.  The change in entropy gives information about the magnitude and direction of a process.  The entropy changes associated with a phase transition reaction can be found by the following equation.

  $\text{ΔS }\text{}\text{=}\text{}\text{}\frac{\text{ΔΗ}}{\text{Τ}}$

Where,

  $\Delta {\rm H}$ is the change in enthalpy of the system

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

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

(b)

Interpretation Introduction

Interpretation:

Using the given idea, the explanation for the given statement has to be given that is when half the water in the cup of tea freezes whiles other half boils.

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 of the system decreases.