Final Answer:
The correct equilibrium expression for this reaction is [Hg₂²⁺] = [Hg₁][Hg²⁺] / [Hg²⁺]
Step-by-step explanation:
The correct equilibrium expression for the given reaction Hg₁ + Hg²⁺(aq) → Hg₂²⁺(aq) is expressed as [Hg₂²⁺] = [Hg₁][Hg²⁺] / [Hg²⁺]. This equation represents the equilibrium concentration of Hg₂²⁺ in the solution formed when metallic mercury reacts with mercury(I) nitrate. The concentration of Hg₂²⁺ is determined by the ratio of the concentrations of Hg₁ and Hg²⁺, emphasizing the role of the reactants in establishing the equilibrium state.
In the equilibrium expression, the square brackets denote the molar concentrations of the species involved in the reaction. The numerator [Hg₁][Hg²⁺] represents the product of the concentrations of metallic mercury (Hg₁) and Hg²⁺, while the denominator [Hg²⁺] signifies the concentration of Hg²⁺ in the solution. The inclusion of these concentrations in the equilibrium expression reflects the stoichiometry of the reaction and how it influences the formation of Hg₂²⁺ at equilibrium.
Therefore, the equilibrium expression accurately describes the relationship between the concentrations of the species involved in the reaction and provides a quantitative understanding of the equilibrium state in the given chemical process involving metallic mercury and mercury(I) nitrate.