Chapter 16, Problem 38QRT

(a)

Interpretation Introduction

Interpretation:

The entropy change for the reaction $2{\text{NH}}_3\left(\text{g}\right)\to {\text{N}}_{\text{2}}\left(\text{g}\right)+3{\text{H}}_{\text{2}}\left(\text{g}\right)$ has to be calculated.

Concept Introduction:

The term entropy is used to represent the randomness in a system.  When a system moves from an ordered arrangement to a less order arrangement, then the entropy of the system increases.  The second law of thermodynamics state that “the entropy of the system either increases or remains the same.”

(b)

Interpretation Introduction

Interpretation:

The entropy change for the reaction $2\text{Na}\left(\text{s}\right)+{\text{Cl}}_{\text{2}}\left(\text{g}\right)\to 2\text{NaCl}\left(\text{s}\right)$ has to be calculated.

Concept Introduction:

Refer to part (a).

(c)

Interpretation Introduction

Interpretation:

The entropy change for the reaction ${\text{H}}_{\text{2}}\left(\text{g}\right)+{\text{I}}_{\text{2}}\left(\text{s}\right)\to 2\text{HI}\left(\text{g}\right)$ has to be calculated.

Concept Introduction:

Refer to part (a).