Please help urgent!!!

Question

Find the concentration of Hg2+2 in 0.010 M KI saturated with Hg2I2 Include activity coefficients in your solubility-product expression. The 𝐾sp of Hg2I2Hg2⁢I2 is 4.6×10−29 Activity coefficients can be found in this table of activity coefficients.

I'm so confused on how to solve these types of problems and calculate concentrations

Answer 1

I will try to help you with this problem but understand that I can’t guarantee its correctness.

Hg2I2 dissociates into Hg2²⁺ + 2I^1-.

The equilibrium equation is Ksp = a_Hg2 x a_I-² (in words, Ksp is equal to the product of the Hg2 ion activity and the iodide ion activity squared).

The activities are equal to the activity coefficients raised to the powers of their coefficients in the dissociation equation given above.

Ksp = γ_Hg2 x C_Hg2 x γ_I-² x C_I-².

Due to the presence of the KI, the concentration of I- can be approximated by the concentration of KI (0.010M). We can get the activity coefficients from the table by looking up the values for the ionic strength = 0.01 for both I- and Hg2^+2.

The solubility equation now becomes Ksp = 0.660 x C_Hg2  x 0.899^2 x 0.010^2.

The only unknown is C_Hg2, so you can solve for it. I got 8.6 x 10^-25 M