# How many equivalents of iodide anion compared to lead cations in PbI_2?

$P b {I}_{2} \left(s\right) r i g h t \le f t h a r p \infty n s P {b}^{2 +} + 2 {I}^{-}$
You have been quoted the concentration of plumbic ions, $P {b}^{2 +}$. It is easy to see why this concentration is equal to the required solubility. As a followup to this question, what do you think the examiner means by "saturated solution"?