Sửa đề 22,4 l => 4,48 l
\(n_{H_2\left(1\right)}=\dfrac{2,24}{22,4}=0,1\left(mol\right)\\ n_{H_2\left(2\right)}=\dfrac{4,48}{22,4}=0,2\left(mol\right)\\ m_Y=m_R\)
PTHH: Ca + 2H2O ---> Ca(OH)2 + H2
0,2<------------------------------0,2
R + 2HCl ---> RCl2 + H2
0,2<------------------------0,2
\(\rightarrow M_R=\dfrac{13,6-0,2.40}{0,2}=24\left(\dfrac{g}{mol}\right)\)
=> R là Mg (t/m)