Chapter 16.4, Problem 16.8P

Interpretation Introduction

Interpretation:

Equilibrium constant for below reaction has to be calculated.

  $\text{2NO}\left(g\right)+{\text{O}}_{\text{2}}\left(g\right)\rightleftharpoons 2{\text{NO}}_2\left(g\right)$

Concept Introduction:

For equilibrium reaction rate of forward reaction is equal to rate of reverse direction. Consider a general reaction that is as follows:

  $a\text{A}+b\text{B}\rightleftharpoons c\text{C}+d\text{D}$

Expression for equilibrium constant is written as follows:

  $K_{\text{eq}}=\frac{{\left[\text{C}\right]}^c{\left[\text{D}\right]}^d}{{\left[\text{A}\right]}^a{\left[\text{B}\right]}^b}$

Here,

$K_{\text{eq}}$ is equilibrium constant

$\left[\text{A}\right]$, $\left[\text{B}\right]$, $\left[\text{C}\right]$ and $\left[\text{D}\right]$ are concentration of substances in reaction

$a$, $b$, $c$ and $d$ are coefficients of substances

Value of equilibrium constant indicates the type of reaction that is forward or reverses that is as follows:

  $\begin{array}{l}{K}_{\text{eq}}>1\left(\text{Forward reaction}\right)\\ K_{\text{eq}}<1\left(\text{Reverse reaction}\right)\end{array}$