\(a)\\ Zn + 2HCl \to ZnCl_2 + H_2\\ 2Al + 6HCl \to 2AlCl_3 + 3H_2\)
\(b)\ n_{Zn} = a\ mol\ ;\ n_{Al} = b\ mol\\ \Rightarrow65a + 27b = 6,6(1)\\ n_{H_2} = a + 1,5b = \dfrac{4,704}{22,4} = 0,21(2)\\ (1)(2)\Rightarrow a = 0,06 ; b = 0,1\\ \Rightarrow m_{Zn} = 0,06.65 = 3,9\ gam\ ;\ m_{Al} = 0,1.27 = 2,7\ gam\)
\(n_{Zn}=a\left(mol\right),n_{Al}=b\left(mol\right)\)
\(m_X=65a+27b=6.6\left(g\right)\left(1\right)\)
\(n_{H_2}=\dfrac{4.704}{22.4}=0.21\left(mol\right)\)
\(Zn+2HCl\rightarrow ZnCl_2+H_2\)
\(2Al+6HCl\rightarrow2AlCl_3+3H_2\)
\(\Rightarrow a+1.5b=0.21\left(2\right)\)
\(\left(1\right),\left(2\right):\)
\(a=0.06\)
\(b=0.1\)
\(m_{Zn}=0.06\cdot65=3.9\left(g\right)\)
\(m_{Al}=0.1\cdot27=2.7\left(g\right)\)