\(n_{Mg}=\dfrac{4,8}{24}=0,2\left(mol\right)\)
\(n_{HCl}=\dfrac{7,3}{36,5}=0,2\left(mol\right)\)
PTHH: Mg + 2HCl --> MgCl2 + H2
Xét tỉ lệ: \(\dfrac{0,2}{1}>\dfrac{0,2}{2}\) => Mg dư, HCl hết
PTHH: Mg + 2HCl --> MgCl2 + H2
0,2------------>0,1
=> VH2 = 0,1.22,4 = 2,24 (l)