My molarity is wrong which keeps me from ding the rest of this problem...any help would be greatly appreciated.
A researcher has a 450.0 mL solution that is 0.421 M in Hg2(NO3)2 and 0.0191 M in Pb(NO3)2. She plans to add solid potassium iodide to separate the mixture by selective precipitation.
Ksp PbI2 = 1.4e-8
Ksp Hg2I2 = 1.2e-28
What is the maximum concentration of iodide ions that may be in solution to achieve the best separation possible?
M [I-]= ?
How many grams of potassium iodide should she add to achieve this?
g of KI
What will the percentage of mercury(I) ions remaining in solution be?
The Attempt at a Solution
hg2i2 = hg2 + 2i
1.2e-28 = [.421]^2
= 1.68e^-14, which is wrong and I have no idea what I am doing wrong