PTHH: \(Fe+H_2SO_4\rightarrow FeSO_4+H_2\)
Ta có: \(n_{Fe}=\dfrac{11,2}{56}=0,2\left(mol\right)\)
Theo PTHH: \(n_{H2SO4}=n_{Fe}=0,2\left(mol\right)\)
\(\Rightarrow m_{H2SO4}=0,2\cdot98=19,6\left(g\right)\)
\(\Rightarrow m_{ddH2SO4}=\dfrac{19,6\cdot100}{98}=20\left(g\right)\)