Chapter 12, Problem 20QRT

(a)

Interpretation Introduction

Interpretation:

The equilibrium constant expression for the heterogenous reaction system ${\text{CaSO}}_4·{\text{5H}}_{\text{2}}{\text{O}}_{\text{(s)}}\rightleftharpoons {\text{ CaSO}}_{\text{4}}·{\text{3H}}_{\text{2}}{\text{O}}_{\text{(s)}}{\text{ + 2H}}_{\text{2}}{\text{O}}_{\text{(g)}}$ has to be written.

Concept Introduction:

Equilibrium constant: At equilibrium the ratio of products to reactants (each raised to the power corresponding to its stoichiometric coefficient) has a constant value, K

For a general reaction,

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

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

The concentration of solids and pure liquids do not change, so their concentration terms are not included in the equilibrium constant expression.

(b)

Interpretation Introduction

Interpretation:

The equilibrium constant expression for the heterogenous reaction system ${\text{SiF}}_{\text{4(g)}}{\text{+ 2H}}_{\text{2}}{\text{O}}_{\text{(g)}}\rightleftharpoons {\text{ SiO}}_{\text{2(s)}}{\text{ + 4HF}}_{\text{(g)}}$ has to be written.

Concept Introduction:

Refer part (a) for concept.

(c)

Interpretation Introduction

Interpretation:

The equilibrium constant expression for the heterogenous reaction system ${\text{LaCl}}_{\text{3(s)}}{\text{ + H}}_{\text{2}}{\text{O}}_{\text{(g)}}\rightleftharpoons {\text{ LaClO}}_{\text{(s)}}{\text{ + 2HCl}}_{\text{(g)}}$ has to be written.

Concept Introduction:

Refer part (a) for concept.