Chapter 15, Problem 92E

Interpretation Introduction

Interpretation:

The value of equilibrium constant $\left({\text{K}}_{\text{eq}}\right)$ can be determined easily with help of the stoichiometric coefficient of the reactants and the products.

Concept Introduction:

For a reaction, equilibrium constant is given by the law of mass action. It is defined as the ratio of concentrations of products to that of reactants each raised to the power of their stoichiometric coefficients. Consider the chemical reaction as follows: $\text{aA}+\text{bB}\rightleftharpoons \text{cC}+\text{dD}$.

The expression for the equilibrium constant for the above reaction is written as

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

Here, $\left[\text{A}\right]$ and $\left[\text{B}\right]$ are the concentrations of the reactants $\text{A}$ and $\text{B}$, $\left[\text{C}\right]$ and $\left[\text{D}\right]$ are the concentrations of the products $\text{C and D}$, and $a,b,c,andd$ are the stoichiometric coefficients. The coefficients given in the chemical equation are represented as exponent in the expression of equilibrium constant.

Equilibrium constant $\left({\text{K}}_{\text{eq}}\right)$ has no unit.