Bài 3 : a ) Zn + H2SO4 \(\rightarrow\)ZnSO4 + H2
b) \(n_{Zn}=\dfrac{m}{M}=\dfrac{26}{65}=0,4\left(mol\right)\)
\(n_{H_2SO_4}=\dfrac{m}{M}=\dfrac{49}{98}=0,5\left(mol\right)\)
Ta thấy : \(\dfrac{n_{Zn}}{1}=0,4< \dfrac{n_{H_2SO_4}}{1}=0,5\)
\(\Rightarrow\)H2SO4 dư sau phản ứng
\(n_{H_2}=n_{Zn}=0,4\left(mol\right)\)
\(\Rightarrow V_{H_2}=n\cdot22,4=0,4\cdot22,4=8,96\left(l\right)\)
c) \(n_{H_2SO_4pư}=n_{Zn}=0,4\left(mol\right)\)
\(\Rightarrow n_{H_2SO_4dư}=n_{H_2SO_4bđ}-n_{H_2SO_4pư}=0,5-0,4=0,1\left(mol\right)\)
\(\Rightarrow m_{H_2SO_4dư}=n\cdot M=0,1\cdot98=9,8\left(g\right)\)
\(n_{ZnSO_4}=n_{Zn}=0,4\left(mol\right)\)
\(\Rightarrow m_{ZnSO_4}=n\cdot M=0,4\cdot161=64,4\left(g\right)\)