\(\left\{{}\begin{matrix}n_{FeCl2}=0,03\left(mol\right)\\n_{FeCl3}=0,05\left(mol\right)\end{matrix}\right.\)
BTNT với Fe và Cl
\(n_{Fe}=n_{FeCl2}+n_{FeCl3}=0,08\left(mol\right)\)
\(n_{Cl^-}=2n_{FeCl2}+3n_{FeCl2}=0,03.2+0,05.3=0,21\left(mol\right)\)
\(H^+\left(axit\right)=n_{Cl^-}=0,21\)
PTHH:
\(2H^++O^{2-}\rightarrow H_2O\)
\(\Rightarrow n_{O^{2-}}=\frac{0,21}{2}=0,105\left(mol\right)\)
\(\Rightarrow m=m_{Fe}+m_O=0,08.56+0,105.16=6,16\left(g\right)\)