Question

Which of the following is an example of heterogeneous equilibrium?

• A. $2S{O}_2\left(g\right)+O_2\left(g\right)\rightleftharpoons 2S{O}_3\left(g\right)$
• B. $C{H}_{3}COOH\left(aq\right)+C{H}_{3}C{H}_{2}OH\left(aq\right)\rightleftharpoons C{H}_{3}COOC{H}_{2}C{H}_3\left(aq\right)+H_{2}O\left(l\right)$
• C. $3Fe\left(s\right)+4H_{2}O\left(g\right)\rightleftharpoons F{e}_3{O}_4\left(s\right)+4H_2\left(g\right)$
• D. All of the above

Answer 1

The correct option is C $3Fe\left(s\right)+4H_{2}O\left(g\right)\rightleftharpoons F{e}_3{O}_4\left(s\right)+4H_2\left(g\right)$

(a) and (b) are examples of homogeneous equilibrium as all the reactants and the products are in the same phase.
(c) is clearly heterogeneous as the phases of all the reactants and the products are not same.


Theory:

Types of equilibrium on the basis of physical state :
1.Homogeneous equilibrium
2.Heterogenous equilibrium


Homogeneous equilibrium :
In Homogeneous equilibrium all reactants and products are in the same phase.
For ex:
$PC{l}_5\left(g\right)\leftrightharpoons PC{l}_3\left(g\right)+C{l}_2\left(g\right)$
Heterogeneous Equilibrium :
In Heterogeneous equilibrium reactants and products are in two or more phases.
For ex. :-
$CaC{O}_3\left(s\right)\leftrightharpoons CaO\left(s\right)+C{O}_2\left(g\right)$
and
$3Fe\left(s\right)+4H_{2}O\left(g\right)\rightleftharpoons F{e}_3{O}_4\left(s\right)+4H_2\left(g\right)$