\(n_{H_2}=0,3\left(mol\right)\)
\(n_X=\dfrac{7,2}{X}\left(mol\right)\)
PTHH: \(2X+nH_2SO_4\rightarrow X_2\left(SO_4\right)_n+nH_2\)
Theo PTHH: \(\dfrac{0,6}{n}=\dfrac{7,2}{X}\Rightarrow X=12n\)
\(n=2\Rightarrow X=24\left(Mg\right)\)
nH2 = 6,72/22,4 = 0,3 mol
X + 2HCl -> XCl2 + H2
=>nX=nH2=0,3 mol
=>MX=7,2/0,3=24
=>X là Mg