PTHH:
\(Fe_xO_y+yH_2\rightarrow xFe+yH_2O\)
\(Fe+2HCl\rightarrow FeCl_2+H_2\)
Ta có:
\(n_{H2}=\frac{6,72}{22,4}=0,3\left(mol\right)\)
\(n_{H\left(trong.HCl\right)}=0,3.2=0,6\left(mol\right)\)
\(n_{Cl\left(trong.HCl\right)}=0,6\left(mol\right)\Rightarrow n_{Cl\left(trong.FeCl2\right)}=\frac{0,6}{2}=0,3\left(mol\right)\)
\(\Rightarrow n_{Fe}=0,3\left(mol\right)\Rightarrow n_{FexOy}=\frac{0,3}{x}\)
\(\Leftrightarrow\frac{0,3}{x}.\left(56x+16y\right)=24\Leftrightarrow16,8+\frac{4,8y}{x}=24\)
\(\Leftrightarrow\frac{4,8y}{x}=7,2\Leftrightarrow\frac{y}{x}=\frac{7,2}{4,8}=\frac{3}{2}\)
\(\Rightarrow\left\{{}\begin{matrix}x=2\\y=3\end{matrix}\right.\)
Vậy CTHH của oxit là Fe2O3
