$7,5(g)\begin{cases} Mg:x(mol)\\ Al: y(mol)\\\end{cases}$ `+V(ml) \ H_2SO_4\ 1M\to 0,35(mol)`
Ta có:
`24x+27y=7,5g(1)`
BTe:
`n_{H_2}=x+1,5y=0,35(mol)(2)`
`(1),(2)=>x=0,2(mol), y=0,1(mol)`
`=> m_{Mg}=0,2.24=4,8g`
`=> m_{Al}=0,1.27=2,7g`
BT nguyên tố `H`
`=> n_{H_2SO_4}=n_{H_2}=0,35(mol)`
`=> V_{H_2SO_4}=\frac{0,35}{1}=0,35(l)=350ml`