Bài làm:
4.
(1) [imath]4P+5O_2 \overset{t^o}{\rightarrow} 2P_2O_5[/imath]
(2) [imath]P_2O_5+3H_2O \to 2H_3PO_4[/imath]
(3)
(4)
(5)
(6) [imath]H_3PO_4+3KOH \to K_3PO_4+3H_2O[/imath]
(7)
(8)
(9) [imath]K_2HPO_4+KOH \to K_3PO_4+H_2O[/imath]
5.
(1) [imath]Zn+2AgNO_3 \to Zn(NO_3)_2+2Ag[/imath]
(2) [imath]Zn(NO_3)_2+Na_2CO_3 \to ZnCO_3 \downarrow+2NaNO_3[/imath]
(3) [imath]ZnCO_3 \overset{t^o}{\rightarrow} ZnO+CO_2[/imath]
(4) [imath]ZnO+2NaOH \to Na_2ZnO_2+2H_2O[/imath]
(5) [imath]CO_2+KOH \to KHCO_3[/imath]
(6) [imath]KHCO_3+KOH \to K_2CO_3+H_2O[/imath]
6.
(1) [imath]4Al+3O_2 \overset{t^o}{\rightarrow} 2Al_2O_3[/imath]
(2) [imath]Al_2O_3+3H_2SO_4 \to Al_2(SO_4)_3+3H_2O[/imath]
(3) [imath]Al_2(SO_4)_3 + 6NaOH \to 2Al(OH)_3 \downarrow+3Na_2SO_4[/imath]
(4) [imath]Al(OH)_3+NaOH \to NaAlO_2+2H_2O[/imath]
(5) [imath]2Al+3Cl_2 \overset{t^o}{\rightarrow} 2AlCl_3[/imath]
(6) [imath]AlCl_3+3AgNO_3 \to Al(NO_3)_3 + 3AgCl \downarrow[/imath]
(7) [imath]Al(NO_3)_3 +3NaOH \to Al(OH)_3 \downarrow+3NaNO_3[/imath]
(8) [imath]2Al(OH)_3 \overset{t^o}{\rightarrow} Al_2O_3+3H_2O[/imath]
(9) [imath]Al_2O_3+2NaOH \to 2NaAlO_2+ H_2O[/imath]
(11) [imath]Al_2O_3+6HCl \to 2AlCl_3+3H_2O[/imath]
(12) [imath]Al_2(SO_4)_3 + 3Ba(NO_3)_2 \to 2Al(NO_3)_3+3BaSO_4\downarrow[/imath]
(13)