\(a,PTHH:Fe+2HCl\rightarrow FeCl_2+H_2\\ \Rightarrow n_{Fe}=n_{FeCl_2}=\dfrac{11,2}{56}=0,2\left(mol\right)\\ \Rightarrow m_{FeCl_2}=0,2\cdot127=25,4\left(g\right)\\ b,n_{H_2}=n_{Fe}=0,2\left(mol\right)\\ \Rightarrow\left\{{}\begin{matrix}m_{H_2}=0,2\cdot2=0,4\left(g\right)\\V_{H_2\left(đktc\right)}=0,2\cdot22,4=4,48\left(l\right)\end{matrix}\right.\)
\(c,PTHH:2H_2+O_2\rightarrow^{t^0}2H_2O\\ \Rightarrow n_{O_2}=\dfrac{1}{2}n_{H_2}=0,1\left(mol\right)\\ \Rightarrow V_{O_2\left(đktc\right)}=0,1\cdot22,4=2,24\left(l\right)\)