a. 

\(\left(1\right)Fe+2HCl--->FeCl_2+H_2\)

\(\left(2\right)FeCl_2+2NaOH--->2NaCl+Fe\left(OH\right)_2\)

\(\left(3\right)4Fe\left(OH\right)_2+O_2+2H_2O\overset{t^o}{--->}4Fe\left(OH\right)_3\)

\(\left(4\right)2Fe\left(OH\right)_3\overset{t^o}{--->}Fe_2O_3+3H_2O\)

\(\left(5\right)Fe_2O_3+6HCl--->2FeCl_3+3H_2O\)

b.

\(\left(1\right)4Al+3O_2\overset{t^o}{--->}2Al_2O_3\)

\(\left(2\right)Al_2O_3+6HCl--->2AlCl_3+3H_2O\)

\(\left(3\right)AlCl_3+3NaOH--->Al\left(OH\right)_3+3NaCl\)

\(\left(4\right)2Al\left(OH\right)_3\overset{t^o}{--->}Al_2O_3+3H_2O\)

\(\left(5\right)Al_2O_3+3H_2SO_4--->Al_2\left(SO_4\right)_3+3H_2O\)

\(b,\left(1\right)4Al+3O_2\rightarrow^{t^o}2Al_2O_3\\ \left(2\right)Al_2O_3+6HCl\rightarrow2AlCl_3+3H_2O\\ \left(3\right)AlCl_3+3NaOH\rightarrow Al\left(OH\right)_3+3NaCl\\ \left(4\right)2Al\left(OH\right)_3\rightarrow^{t^o}Al_2O_3+3H_2O\\ \left(5\right)Al_2O_3+3H_2SO_4\rightarrow Al_2\left(SO_4\right)_3+3H_2O\)

\(a,\left(1\right)Fe+2HCl\rightarrow FeCl_2+H_2\\ \left(2\right)FeCl_2+2NaOH\rightarrow Fe\left(OH\right)_2+2NaCl_2\\ \left(3\right)4Fe\left(OH\right)_2+O_2+2H_2O\rightarrow4Fe\left(OH\right)_3\\ \left(4\right)2Fe\left(OH\right)_3\rightarrow^{t^o}Fe_2O_3+3H_2O\\ \left(5\right)Fe_2O_3+6HCl\rightarrow2FeCl_3+3H_2O\)

Bài 4,7,8 đang lỗi text ,em xem lại

a)

\(Mg\left(OH\right)_2\underrightarrow{t^o}MgO+H_2O\)

\(MgO+H_2SO_4\rightarrow MgSO_4+H_2O\)

\(MgSO_4+BaCl_2\rightarrow BaSO_4\downarrow+MgCl_2\)

\(MgCl_2+2NaOH\rightarrow Mg\left(OH\right)_2\downarrow+2NaCl\)

b)

\(2Al_2O_3\xrightarrow[criolit]{npnc}4Al+3O_2\)

\(2Al+6HCl\rightarrow2AlCl_3+3H_2\)

\(AlCl_3+3AgNO_3\rightarrow Al\left(NO_3\right)_3+3AgCl\downarrow\)

\(4Al\left(NO_3\right)_3\underrightarrow{t^o}2Al_2O_3+12NO_2+3O_2\)

\(Al_2O_3+3H_2SO_4\rightarrow Al_2\left(SO_4\right)_3+3H_2O\)

a.

2Al2O3 \(\underrightarrow{t^o}\)4Al + 3O2\(\uparrow\)

Al + 6HNO3 \(\rightarrow\) Al(NO3)3\(\downarrow\) + 3NO2 + 3H2O

Al(NO3)3 + NaOH \(\rightarrow\) Al(OH)3\(\downarrow\) + NaNO3

2Al(OH)3 \(\xrightarrow[criolit]{đpnc}\) Al2O3 + 3H2O

Al2O3 + 3H2SO4 \(\rightarrow\) Al2(SO4)3 + 3H2O

Al2(SO4)3 + 3BaCl2 \(\rightarrow\) 3BaSO4\(\downarrow\) + 2AlCl3

2AlCl3 \(\xrightarrow[criolit]{đpnc}\) 2Al + 3Cl2\(\uparrow\)

2Al + 3CuSO4 \(\rightarrow\) 3Cu + Al2(SO4)3

C.

\(a,4Al+3O_2\xrightarrow[t^0]{}2Al_2O_3\\ Al_2O_3+6HCl\rightarrow2AlCl_3+3H_2O\\ AlCl_3+3AgNO_3\rightarrow Al\left(NO_3\right)_3+3AgCl\\ AlCl_3+3NaOH\rightarrow Al\left(OH\right)_3+3NaCl\\ 2Al\left(OH\right)_3\xrightarrow[t^0]{}Al_2O_3+3H_2O\\ 2Al_2O_3\xrightarrow[đpnc]{criolit}4Al+3O_2\\ b,3Fe+2O_2\xrightarrow[t^0]{}Fe_3O_4\\ Fe_3O_4+8HCl\rightarrow2FeCl_3+FeCl_2+4H_2O\\ FeCl_3+3NaOH\rightarrow Fe\left(OH\right)_3+3NaCl\\ 2Fe\left(OH\right)_3\xrightarrow[t^0]{}Fe_2O_3+3H_2O\\ Fe_2O_3+3CO\xrightarrow[t^0]{}2Fe+3CO_2\)

\(c,2Fe\left(OH\right)_3+3H_2SO_4\rightarrow Fe_2\left(SO_4\right)_3+6H_2O\\ Fe_2\left(SO_4\right)_3+3BaCl_2\rightarrow2FeCl_3+3BaSO_4\\ FeCl_3+AgNO_3\rightarrow Fe\left(NO_3\right)_3+3AgCl\)