Freshly precipiteated Al and Mg hydroxides are stirred vigorously in a buffer solution containing `0.25M` of `NH_(4)CI` and `0.05M` of `NH_(4)OH`. Calculate `[Al^(3+)]` and `[Mg^(2+)]` in solution. `K_(b)` for `NH_(4)OH=1.8xx10^(-5) K_(SP)` of `Al(OH)_(3)=6xx10^(-32)` and `K_(SP)` of `Mg(OH)_(2)=8.9xx10^(-12)`.