Question

Answer 1

$D$

$2Na+2H_2O\to 2NaOH+H_2$

$Al_2(SO_4)_3+6NaOH\to 2Al(OH)_3\downarrow+3Na_2SO_4$

$Al(OH)_3+NaOH\to NaAlO_2+2H_2O$

(do $NaOH$ dư nên hòa tan hết kết tủa trắng $Al(OH)_3$)

Answer 2

D

2Na+2H2O->2NaOH+H2

6NaOH+Al2(SO4)3->2Na2SO4+3Al(OH)3

AL(OH)3+NaOH->NaAlO2+2H2O