Question

   Viết PTHH ghi rõ điều kiện xảy ra phản ứng (nếu có)

                                              (1)                (2)               (3)                     (4)

a/                             Al₂O_{3 -->}  Al -->  Al(NO)₃    -->   Al(OH)₃ -->    NaAlO₂

 b/                           Fe   -->   FeCl₃  -->  Fe(NO₃)₃   -->  Fe(OH)₃  -->  Fe₂O₃

 

c/                                   FeCl₂  --> Fe(NO₃)₂ -->    Fe(OH)₂ -->Fe₂O₃  -->  Fe₂(SO₄)₃     

d/                                  Fe   -->      FeCl₂   -->    Fe(OH)₂     -->    Fe(OH)₃  -->     Fe₂(SO₄)₃.

Answer 1

a) 

\(2Al_2O_3\underrightarrow{t^o,criolit}4Al+3O_2\)

\(Al+3AgNO_3\rightarrow Al\left(NO_3\right)_3+3Ag\)

\(Al\left(NO_3\right)_3+3NaOH\rightarrow Al\left(OH\right)_3\downarrow+3NaNO_3\)

\(Al\left(OH\right)_3+NaOH\rightarrow NaAlO_2+2H_2O\)

b) 

\(2Fe+3Cl_2\underrightarrow{t^o}2FeCl_3\)

\(FeCl_3+3AgNO_3\rightarrow Fe\left(NO_3\right)_3+3AgCl\downarrow\)

\(Fe\left(NO_3\right)_3+3NaOH\rightarrow Fe\left(OH\right)_3\downarrow+3NaNO_3\)

\(2Fe\left(OH\right)_3\underrightarrow{t^o}Fe_2O_3+3H_2O\)

 

c) 

\(FeCl_2+2AgNO_3\rightarrow Fe\left(NO_3\right)_2+2AgCl\downarrow\)

\(Fe\left(NO_3\right)_2+2NaOH\rightarrow Fe\left(OH\right)_2\downarrow+2NaNO_3\)

\(4Fe\left(OH\right)_2+O_2\underrightarrow{t^o}2Fe_2O_3+4H_2O\)

\(Fe_2O_3+3H_2SO_4\rightarrow Fe_2\left(SO_4\right)_3+3H_2O\)

d)

\(Fe+2HCl\rightarrow FeCl_2+H_2\)

\(FeCl_2+2NaOH\rightarrow Fe\left(OH\right)_2\downarrow+2NaCl\)

\(4Fe\left(OH\right)_2+O_2+2H_2O\rightarrow4Fe\left(OH\right)_3\)

\(2Fe\left(OH\right)_3+3H_2SO_4\rightarrow Fe_2\left(SO_4\right)_3+6H_2O\)

Answer 2

a) 

\(2Al_2O_3\underrightarrow{t^o,criolit}4Al+3O_2\)

\(Al+3AgNO_3\rightarrow Al\left(NO_3\right)_3+3Ag\)

\(Al\left(NO_3\right)_3+3NaOH\rightarrow Al\left(OH\right)_3\downarrow+3NaNO_3\)

\(Al\left(OH\right)_3+NaOH\rightarrow NaAlO_2+2H_2O\)

b) 

\(2Fe+3Cl_2\underrightarrow{t^o}2FeCl_3\)

\(FeCl_3+3AgNO_3\rightarrow Fe\left(NO_3\right)_3+3AgCl\downarrow\)

\(Fe\left(NO_3\right)_3+3NaOH\rightarrow Fe\left(OH\right)_3\downarrow+3NaNO_3\)

\(2Fe\left(OH\right)_3\underrightarrow{t^o}Fe_2O_3+3H_2O\)

\(Fe_2O_3+3H_2SO_4\rightarrow Fe_2\left(SO_4\right)_3+3H_2O\)

d)

\(Fe+2HCl\rightarrow FeCl_2+H_2\)

\(FeCl_2+2NaOH\rightarrow Fe\left(OH\right)_2\downarrow+2NaCl\)

\(4Fe\left(OH\right)_2+O_2+2H_2O\rightarrow4Fe\left(OH\right)_3\)

\(2Fe\left(OH\right)_3+3H_2SO_4\rightarrow Fe_2\left(SO_4\right)_3+6H_2O\)