Chapter 5, Problem 5G.3BST

Interpretation Introduction

Interpretation:

The equilibrium constant for the given reaction has to be written.

  ${\text{Zn}}_{\left(\text{s}\right)}\text{+}\text{2}{\text{HCl}}_{\left(\text{aq}\right)}\rightleftharpoons {\text{ZnCl}}_{\text{2}\left(\text{aq}\right)}\text{+}{\text{H}}_{\text{2}\left(\text{g}\right)}$

Concept Introduction:

The equilibrium constant, $\text{K}$, is characteristic of the composition of reaction mixture at equilibrium at a given temperature irrespective of the initial composition of reaction mixture.

For the reaction,

  $\text{a}{\text{A}}_{\left(\text{g}\right)}\text{+}\text{b}{\text{B}}_{\left(\text{g}\right)}\rightleftharpoons \text{c}{\text{C}}_{\left(\text{g}\right)}\text{+}\text{d}{\text{D}}_{\left(\text{g}\right)}$

The equilibrium constant can be written as

  $\text{K}\text{=}\frac{{\left({\text{P}}_{\text{C}}\right)}^{\text{c}}{\left({\text{P}}_{\text{D}}\right)}^{\text{d}}}{{\left({\text{P}}_{\text{A}}\right)}^{\text{a}}{\left({\text{P}}_{\text{B}}\right)}^{\text{b}}}$

In the equilibrium constant of reactions that involves phases other than gases, pure solids and liquids do not appear in the expression.