Question

Including activity coefficients, find the [Hg²²⁺] in saturated Hg₂Br₂ in (a) water, (b) 0.00100 M KNO₃, and (c) 0.00100 M KBr

Answer 1

The concentration of Hg²²⁺ in a saturated Hg₂Br₂ solution can be estimated using the Ksp, but accurate values in different mediums require activity coefficients, which account for ion interactions in solution.

Step-by-step explanation:

To estimate the concentration of Hg²²⁺ and Br⁺ in a saturated solution of Hg₂Br₂ with the solubility product (Ksp) of 5.6 x 10⁻²³, the dissolution reaction would be:

Hg₂Br₂(s) → Hg²²⁺(aq) + 2 Br⁺(aq)

Under the given conditions, the concentrations can be expressed by the equilibrium expression Ksp = [Hg²²⁺] × [Br⁺]². However, activity coefficients are needed for accurate concentrations in different solutions like water, KNO₃, and KBr. These coefficients take into account interactions among ions in solution and are crucial when ionic strength is significant.

Without specific values for the activity coefficients, the precise concentrations of Hg²²⁺ in each scenario cannot be calculated. Typically, activity coefficients decrease the effective concentration of ions in solution compared to their analytical concentration.