a, Ta có: \(n_{H_2}=0,25\left(mol\right)\)
PT: \(A+2HCl\rightarrow ACl_2+H_2\)
___0,25_______________0,25 (mol)
\(\Rightarrow M_A=\dfrac{16,25}{0,25}=65\left(g/mol\right)\)
Vậy: A là Zn.
b, PT: \(Zn+H_2SO_4\rightarrow ZnSO_4+H_2\)
_____0,25___________________0,25 (mol)
\(\Rightarrow V_{H_2\left(LT\right)}=0,25.22,4=5,6\left(l\right)\)
Mà: VH2 (thực tế) = 5,04 (l)
\(\Rightarrow H\%=\dfrac{5,04}{5,6}.100\%=90\%\)
Bạn tham khảo nhé!