Question

Determine the concentrations of hg22 and cl– in a saturated solution of hg2cl2 in

a.pure water (assume μ = 0).

Answer 1

To solve this, we need the solubility constant for Hg2Cl2, which is:

Ksp = 1.4 x 10^-18

The ionic formula would be:

Hg2Cl2(s) ---> Hg2 2+(aq) + 2Cl-(aq)

Therefore the total amounts of ions produced = x M Hg2 2+ and 2x M Cl-

The formula for Ksp in this case is:

Ksp = [Hg2 2+] [Cl-]^2

1.4 x 10^-18 = (x) * (2x)^2

1.4 x 10^-18 = 4x^3
x = 7.0 x 10^-7 M = [Hg2 2+]

2x = 14 x 10^-7 M = [Cl-]