Answer:
k = [tex]\frac{[HOCl]^2}{[Cl]^2}[/tex]
Explanation:
The equilibrium-constant expression is defined as the ratio of the concentration of products over concentration of reactants. Each concentration is raised to the power of their coefficient.
Also, pure solid and liquids are not included in the equilibrium-constant expression because they don't affect the concentration of chemicals in the equilibrium
The global reaction is:
2 HgO (s) + H₂O (l) +2 Cl₂ (g) ⇌ 2 HOCl (aq) + HgO⋅HgCl₂ (s)
Thus, equilibrium-constant expression is:
k = [tex]\frac{[HOCl]^2}{[Cl]^2}[/tex]
You don't include HgO nor HgO⋅HgCl₂ because are pure solids nor water because is pure liquid.
I hope it helps!