nMgCl2 =0,02 mol
nAlCl3 =0,01 mol
nNaOH =0,08 mol
MgCl2 + 2NaOH -> Mg(OH)2 + 2NaCl
0,02..........0,04.............0,02
AlCl3 + 3NaOH -> Al(OH)3 + 3NaCl
0,01...........0,03...........0,01
NaOH + Al(OH)3 -> NaAlO2 + 2H2O
0,01..........0,01
=> m kt =m Mg(OH)2 =............ (vì Al(OH)3 đã bị tan hết )