You have a Lead(II) chromate solution with a concentration of 1.64e-07 mol/L. How many moles of chromate ions do you have to add to just about start precipitation of lead chromate assuming the volume does not change appreciably?
n(CrO4^2-)= ? mol
It shows how to calculate the moles of CrO42- ions, which are added to Lead(II) chromate solution to make it just about start precipitation. The solution is detailed and was rated '5/5' by the student who originally posted the question.