- Quá trình: \[CO+\underbrace{F{{e}_{2}}{{O}_{3}}}_{m\ (g)}\xrightarrow{{{t}^{o}}}\underbrace{Fe,O}_{{{m}_{1}}\ (g)\ hh\ Y}\xrightarrow{+HN{{O}_{3}}}\underbrace{F{{e}^{3+}},NO_{3}^{-}}_{({{m}_{1}}+\ 16,68)\ g\ mu\grave{e}i\ Z}\ +\ \overbrace{NO}^{0,02\ mol}+\ {{H}_{2}}O\]

- Ta có: n_{e nhận} = ${{n}_{NO_{3}^{-}}}=3{{n}_{NO}}+2{{n}_{O}}=0,06+2{{n}_{O}}\Rightarrow {{m}_{Z}}={{m}_{1}}+16,68=56{{n}_{Fe}}+62{{n}_{NO_{3}^{-}}}$ (1)

mà ${{m}_{Y}}={{m}_{1}}=56{{n}_{Fe}}+16{{n}_{O}}$ thay m₁ vào (1) suy ra: n_O = 0,12 mol

$\xrightarrow{BT:\ e}{{n}_{Fe}}=\frac{3{{n}_{NO}}+2{{n}_{O}}}{3}=0,1\ mol$ $\xrightarrow{BT:\ Fe}{{n}_{F{{e}_{2}}{{O}_{3}}}}=\frac{{{n}_{Fe}}}{2}=0,05\ mol\Rightarrow {{m}_{F{{e}_{2}}{{O}_{3}}}}=8\ (g)$