a
PTHH:
\(Mg+2HCl\rightarrow MgCl_2+H_2\)
\(2R+6HCl\rightarrow2RCl_3+3H_2\)
b
BT Cl: \(m_{Cl}=m_{muối}-m_{hh}=32,35-7,5=24,85\left(g\right)\)
\(\Rightarrow n_{Cl}=n_{HCl}=\dfrac{24,85}{35,5}=0,7\left(mol\right)\)
BT H: \(n_{H_2}=\dfrac{1}{2}n_{HCl}=\dfrac{1}{2}.0,7=0,35\left(mol\right)\)
\(\Rightarrow V_{H_2}=0,35.22,4=7,84\left(l\right)\)