Question

If HCl were added to a solution containing lead(II) ions, sodium ions, nickel(II) ions, and potassium ions, which ions would precipitate? (Select all that apply.)
lead ions
nickel ions
potassium ions
sodium ions
none of them

Answer 1

look at the solubilities (or \(K_{sp}\)) of the combinations of the cations with \(Cl^-\).

for example: lead(II) and the chloride ion make: \(PbCl_2\) ; Ksp=\(1.7*10^{−5}\) which is pretty low. Since they didn't give you actual concentrations, you can assume it will ppt.