\(\%O=100\%-28\%-24\%=28\%0\)
\(m_{Fe}=\dfrac{28\%.400}{100\%}=112\left(g\right)\Rightarrow n_{Fe}=\dfrac{m}{M}=\dfrac{112}{56}=2\left(mol\right)\)
\(m_S=\dfrac{24\%.400}{100\%}=96\left(g\right)\Rightarrow n_S=\dfrac{m}{M}=\dfrac{96}{32}=3\left(mol\right)\)
\(m_O=\dfrac{48\%.400}{100\%}=192\left(g\right)\Rightarrow n_O=\dfrac{m}{M}=\dfrac{192}{16}=12\left(mol\right)\)
\(\Rightarrow CTHH:Fe_2S_3O_{12}\) hay \(Fe_2\left(SO_4\right)_3\)
Trong 1 mol hợp chất B có:
mFe=\(\dfrac{400.28}{100}\)=112(g)⇒nFe=\(\dfrac{112}{56}\)=2(mol)
mS=\(\dfrac{400.24}{100}\)=96(g)⇒nS=\(\dfrac{96}{32}\)=3(mol)
mO=400-(112+96)=192(g)⇒no=\(\dfrac{192}{16}\)=12(mol)
Vậy CTHH của hợp chất B là Fe2(SO4)3