Chapter 20, Problem 20.87P

Interpretation Introduction

Interpretation:

The sign of ${\text{ΔS}}^{\text{o}}$ and $\Delta G^o$ change expected for given reaction process and which drives the reaction have to be predicted.

Concept introduction:

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.

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 $\Delta S>0$ positive

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

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