Chapter 18, Problem 18.142MP

Interpretation Introduction

(a)

Interpretation:

Partial pressure of ${\text{NO}}_{\text{2}}$ and ${\text{N}}_2{\text{O}}_4$ at equilibrium is to be calculated.

Concept introduction:

The formula that determines spontaneity of the reaction is,

$\Delta G°=\Delta H°-T\Delta S°$

The expression to evaluate free energy from equilibrium constant is as follows:

$\Delta G°=-RT\ln K$

Where,

• $K$ represents equilibrium constant.
• $\Delta G°$ denotes standard free energy change.
• $R$ denotes gas constant.
• $T$ denotes temperature.
• $\Delta S°$ denotes entropy change of reaction.
• $\Delta H°$ denotes enthalpy change of reaction.

Interpretation Introduction

(b)

Interpretation:

Shape of ${\text{N}}_2{\text{O}}_4$ and hybrid orbitals used by $\text{N}$ atoms should be determined.

Concept introduction:

Double bonded molecule is regarded as $s{p}^2$ hybridized. The geometry adopted is trigonal planer such as there is least amount of lone pair-bond pair repulsions.