A solution is 0.10 M in `Ag^(+), Ca^(2+), Mg^(2+)` and `Al^(3+)` ions. Which compound will precipitate at the lowest `[PO_(4)^(3-)]` when a solution of `Na_(3)PO_(4)` is added ?

Options

A. `Ag_(3)PO_(4) (K_(sp) = 1 xx 10^(-6))`
B. `Ca_(3) (PO_(4))_(2) (K_(sp) = 1 xx 10^(-33))`
C. `Mg_(3) (PO_(4))_(2) (K_(sp) = 1 xx 10^(-24))`
D. `AIPO_(4) (K_(sp) = 1 xx 10^(-20))`

Answer

D