Solubility of Hg2Br2
The molar solubility of Hg2Br2 is calculated to be 7.7 × 10-20 M, which is greater than the value of 2.2 × 10-20 M that was calculated when the effect of ionic strength was ignored.
The ionic strength of the solution was taken into account by calculating the activity coefficients for Hg2+ and Br–. The activity coefficients were calculated using the values of alpha from Table 6.2.
The ionic strength-adjusted Ksp for the solubility of Hg2Br2 was then calculated and found to be 5.6 × 10-23. This value was used to solve for the molar solubility of Hg2Br2, which was found to be 7.7 × 10-20 M.