Ta có: \(n_{hhk}=\dfrac{69,412}{24,79}=2,8\left(mol\right)\) = nNO2 + nCO2
56nFe + 12nC = 11,6 (1)
BT e, có: 3nFe + 4nC = nNO2 (2)
BTNT: nCO2 = nC
⇒ nNO2 + nC = 2,8 (3)
Từ (1), (2) và (3) \(\Rightarrow\left\{{}\begin{matrix}n_{Fe}=0,1\left(mol\right)\\n_C=0,5\left(mol\right)\\n_{NO_2}=2,3\left(mol\right)\end{matrix}\right.\)
\(\Rightarrow\left\{{}\begin{matrix}m_{Fe}=0,1.56=5,6\left(g\right)\\m_C=0,5.12=6\left(g\right)\end{matrix}\right.\)