\(n_{Fe}=\dfrac{12}{56}=\dfrac{3}{14}\left(mol\right)\)
\(Fe+H_2SO_4\rightarrow FeSO_4+H_2\)
\(\dfrac{3}{14}....\dfrac{3}{14}.......\dfrac{3}{14}......\dfrac{3}{14}\)
\(m_{FeSO_4}=\dfrac{3}{14}\cdot152=32.57\left(g\right)\)
\(V_{H_2}=\dfrac{3}{14}\cdot22.4=4.8\left(l\right)\)
\(m_{dd_{H_2SO_4}}=\dfrac{\dfrac{3}{14}\cdot98}{19.6\%}=107.1\left(g\right)\)