a, Gọi \(\left\{{}\begin{matrix}n_{Al}=a\left(mol\right)\\n_{Mg}=b\left(mol\right)\end{matrix}\right.\left(a,b>0\right)\)
\(n_{H_2SO_4}=\dfrac{68,6}{98}=0,7\left(mol\right)\)
PTHH:
2Al + 3H2SO4 ---> Al2(SO4)3 + 3H2
a----->1,5a
2Mg + O2 --to--> 2MgO
b-------------------->b
4Al + 3O2 --to--> 2Al2O3
a-------------------->0,5a
b, => hệ pt \(\left\{{}\begin{matrix}27a+24b=15\\1,5a+b=0,7\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}a=0,2\left(mol\right)\\b=0,4\left(mol\right)\end{matrix}\right.\left(TM\right)\)
\(\rightarrow\left\{{}\begin{matrix}m_{Al_2O_3}=0,2.0,5.102=10,2\left(g\right)\\m_{MgO}=0,4.40=16\left(g\right)\end{matrix}\right.\)
