\(a,n_{Zn}=\dfrac{19,5}{65}=0,3mol\\ Zn+2HCl\rightarrow ZnCl_2+H_2\\ n_{H_2}=n_{Zn}=0,3mol\\ V_{H_2}=0,3.24,79=7,437l\\ b,FeO+H_2\xrightarrow[t^0]{}Fe+H_2O\\ n_{FeO}=\dfrac{19,2}{72}=\dfrac{4}{15}mol\\ \Rightarrow\dfrac{0,3}{1}>\dfrac{4:15}{1}\Rightarrow H_2.dư\\ n_{Fe}=n_{FeO}=\dfrac{4}{15}mol\\ m_{Fe}=\dfrac{4}{15}.56\approx14,93g\)