Mình làm mẫu 2 ý đầu thôi nhé
a)
\(CO:\left\{{}\begin{matrix}\%m_C=\dfrac{12}{28}.100\%=42,86\%\\\%m_O=100\%-42,86\%=57,14\%\end{matrix}\right.\\ FeS_2:\left\{{}\begin{matrix}\%m_{Fe}=\dfrac{56}{120}.100\%=46,67\%\\\%m_S=100\%-46,67\%=53,33\%\end{matrix}\right.\)
\(MgCl_2:\left\{{}\begin{matrix}\%m_{Mg}=\dfrac{24}{95}.100\%=25,26\%\\\%m_{Cl}=100\%-25,56\%=74,74\%\end{matrix}\right.\\ Cu_2O:\left\{{}\begin{matrix}\%m_{Cu}=\dfrac{128}{144}.100\%=88,89\%\\\%m_O=100\%-88,89\%=11,11\%\end{matrix}\right.\)
\(CO_2:\left\{{}\begin{matrix}\%m_C=\dfrac{12}{44}.100\%=27,27\%\\\%m_O=100\%-27,27\%=72,73\%\end{matrix}\right.\\ C_2H_4:\left\{{}\begin{matrix}\%m_C=\dfrac{24}{28}.100\%=85,71\%\\\%m_O=100\%-85,71\%=14,29\%\end{matrix}\right.\\ C_6H_6:\left\{{}\begin{matrix}\%m_C=\dfrac{72}{78}.100\%=92,31\%\\\%m_H=100\%-92,31\%=7,69\%\end{matrix}\right.\)
b)
\(FeO:\left\{{}\begin{matrix}\%m_{Fe}=\dfrac{56}{72}.100\%=77,78\%\\\%m_O=100\%-77,78\%=22,22\%\end{matrix}\right.\\ Fe_3O_4\left\{{}\begin{matrix}\%m_{Fe}=\dfrac{168}{232}.100\%=72,41\%\\\%m_O=100\%-72,41\%=27,59\%\end{matrix}\right.\\ Fe_2O_3\left\{{}\begin{matrix}\%m_{Fe}=\dfrac{112}{160}.100\%=70\%\\\%m_O=100\%-70\%=30\%\end{matrix}\right.\)
\(Fe\left(OH\right)_2:\left\{{}\begin{matrix}\%m_{Fe}=\dfrac{56}{90}.100\%=62,22\%\\\%m_O=\dfrac{32}{90}.100\%=35,56\%\\\%m_H=\left(100-62,22-35,56\right)\%=2,22\%\end{matrix}\right.\)
\(Fe\left(OH\right)_3:\left\{{}\begin{matrix}\%m_{Fe}=\dfrac{56}{107}.100\%=52,34\%\\\%m_O=\dfrac{48}{107}.100\%=44,86\%\\\%m_H=\left(100-52,34-44,86\right)\%=2,8\%\end{matrix}\right.\)
