\(M_{MgSO_4}=24+32+16\times4=120\left(g\right)\)
\(\%Mg=\dfrac{24}{120}\times100\%=20\%\)
\(\%S=\dfrac{32}{120}\times100\%=26,67\%\)
\(\%O=100\%-20\%-26,67\%=53,33\%\)
\(M_{CuO}=64+16=80\left(g\right)\)
\(\%Cu=\dfrac{64}{80}\times100\%=80\%\)
\(\%O=100\%-80\%=20\%\)
\(M_{Cu\left(NO_3\right)_2}=64+2\times\left(14+16\times3\right)=188\left(g\right)\)
\(\%Cu=\dfrac{64}{188}\times100\%=34,04\%\)
\(\%N=\dfrac{14\times2}{188}\times100\%=14,89\%\)
\(\%O=100\%-34,04\%-14,89\%=51,07\%\)
+) \(MgSO_4\)
\(M_{MgSO_4}=24+32+16.4=120\left(g/mol\right)\)
\(\Rightarrow\left\{{}\begin{matrix}\%m_{Mg}=\dfrac{24.100\%}{120}=20\%\\\%m_S=\dfrac{32.100\%}{120}=26,6\%\\\%m_O=\dfrac{64.100\%}{120}=53,3\%\end{matrix}\right.\)
+) \(CuO\)
\(M_{CuO}=64+16=80\left(g/mol\right)\)
\(\Rightarrow\left\{{}\begin{matrix}\%m_{Cu}=\dfrac{64.100\%}{80}=80\%\\\%m_O=\dfrac{16.100\%}{80}=20\%\end{matrix}\right.\)
+) \(Cu\left(NO_3\right)_2\)
\(M_{Cu\left(NO_3\right)_2}=64+2.\left(14+16.3\right)=64+2.62=188\left(g/mol\right)\)
\(\Rightarrow\left\{{}\begin{matrix}\%m_{Cu}=\dfrac{64.100\%}{188}=34\%\\\%m_N=\dfrac{28.100\%}{188}=14,8\%\\\%m_O=\dfrac{96.100\%}{188}=51\%\end{matrix}\right.\)
