\(n_{HCl}=\dfrac{10,005.21,9\%}{36,5}\approx0,06\left(mol\right)\)
CTHH: RxOy
\(PTHH:R_xO_y+2yHCl\rightarrow xRCl_{\dfrac{2y}{x}}+yH_2O\)
\(\dfrac{0,06}{2y}\)<-0,06
=> \(M_{R_xO_y}=x.M_R+16y=\dfrac{2,16}{\dfrac{0,06}{2y}}=72y\left(g/mol\right)\)
=> \(M_R=28.\dfrac{2y}{x}\left(g/mol\right)\)
Xét \(\dfrac{2y}{x}=2\) thỏa mãn => MR = 56 (g/mol)
=> R là Fe (Sắt)
=> CTHH: FeO