Chapter 17.4, Problem 17.4BFP

Interpretation Introduction

Interpretation:

From the equilibrium reaction mixture represented in given scene 1, the direction of the reaction to which the reaction mixtures in scene 2 and 3 will proceed has to be determined.

Concept Introduction:

Reaction Quotient:

Reaction quotient, Q is the ratio between product of the product concentration to the product of the reactant concentration with each term raised to the power of its balancing coefficient.

Consider a general equation,

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

Where a, b, c and d are the stoichiometric coefficients.  The reaction quotient is,

  ${\text{Q}}_{\text{c}}\text{ = }\frac{{\text{[C]}}^{\text{c}}{\text{[D]}}^{\text{d}}}{{[\text{A]}}^{\text{a}}{\text{[B]}}^{\text{b}}}$

Comparison of $\text{Q and K}$ :

When $\text{Q < K}$, the reaction will proceed in right direction, $\text{reactants}\stackrel{}{\to }\text{products}$

When $\text{Q > K}$, the reaction will proceed in left direction, $\text{reactants}\stackrel{}{\leftarrow }\text{products}$

When $\text{Q = K}$, the reaction will remain unchanged, $\text{reactants}\stackrel{}{\rightleftharpoons }\text{products}$