Chapter 20.2, Problem 20.2AFP

(a)

Interpretation Introduction

Interpretation: The given reaction needs to be balanced and the sign of change in entropy of the reaction and its value needs to be calculated at 298 K.

  $\text{NO}\left(g\right)\to {\text{N}}_{\text{2}}\text{O}\left(g\right)+{\text{N}}_{\text{2}}{\text{O}}_{\text{3}}\left(g\right)$

Concept Introduction: A chemical reaction is said to be balanced if there are an equal number of atoms of the same type on both sides of the chemical equation. The sign of change in entropy of a reaction depends on the number of gaseous species on the reactant and product side. If the number of gaseous species is more on the product side, the sign will be positive; but if there is a greater number of gaseous species on the left or reactant side, the sign of change in entropy of reaction is negative. Also, the change in entropy of a reaction can be calculated as follows:

  $\Delta S_{\text{rxn}}={\displaystyle \sum S_{\text{product}}}-{\displaystyle \sum S_{\text{reactant}}}$

Here, ${\displaystyle \sum S_{\text{product}}}$ is sum of entropies of species on product side and ${\displaystyle \sum S_{\text{reactant}}}$ is sum of entropies of species on reactant side.

(b)

Interpretation Introduction

Interpretation: The given reaction needs to be balanced and the sign of change in entropy of the reaction and its value needs to be calculated at 298 K.

  ${\text{CH}}_{\text{3}}\text{OH}\left(g\right)\to \text{CO}\left(g\right)+{\text{H}}_{\text{2}}\left(g\right)$

Concept Introduction: A chemical reaction is said to be balanced if there are an equal number of atoms of the same type on both sides of the chemical equation. The sign of change in entropy of a reaction depends on the number of gaseous species on the reactant and product side. If the number of gaseous species is more on the product side, the sign will be positive; but if there is a greater number of gaseous species on the left or reactant side, the sign of change in entropy of reaction is negative. Also, the change in entropy of a reaction can be calculated as follows:

  $\Delta S_{\text{rxn}}={\displaystyle \sum S_{\text{product}}}-{\displaystyle \sum S_{\text{reactant}}}$

Here, ${\displaystyle \sum S_{\text{product}}}$ is sum of entropies of species on product side and ${\displaystyle \sum S_{\text{reactant}}}$ is sum of entropies of species on reactant side.