\(M=242+132=374(đvc)\\ \%_{Fe}=\frac{56}{374}.100=14,97\%\\ \%_{N}=\frac{14.3+14.2}{374}.100=18,72\%\\ \%_H=\frac{1.4.2}{374}.100=2,14\%\\ \%_S=\frac{32}{374}.100=8,57\%\\ \%_O=55,6\%\)
\(Fe(NO_3)_3\\ \%_{Fe}=\frac{56}{242}.100\%=23,14\%\\ \%_N=\frac{14.3}{242}.100\%=17,36\%\\ \%_O=595,5\%\\ (NH_4)_2SO_4\\ \%N=\frac{14.2}{132}=21,21\% \\ \%H=\frac{(1.4).2.}{132}=6,06\% \\ \%S=\frac{32}{132}=24,24\% \\ \%O=\frac{16.4}{132}=48,49\%\\ \)