Chapter 1, Problem 1.26P

Interpretation Introduction

Interpretation:

The reason why equilibrium constants are dimensionless has to be given.

Concept Introduction:

Equilibrium constant$\left({\text{K}}_{\text{c}}\right)$:

Equilibrium constant $\left({\text{K}}_{\text{c}}\right)$ is the ratio of the rate constants of the forward and reverse reactions at a given temperature.  In other words it is the ratio of the concentrations of the products to concentrations of the reactants.  Each concentration term is raised to a power, which is same as the coefficients in the chemical reaction.

Consider the reaction where A and B reacts to give C and D.

    $\text{aA + bB}\rightleftharpoons \text{cC + dD}$

    ${\text{Equilibrium constant (K}}_{\text{c}}\text{) = }\frac{{\text{[C]}}^c{\text{[D]}}^d}{{\text{[A]}}^a{\text{[B]}}^b}$