\(n_{Al}=\dfrac{2,7}{27}=0,1\left(mol\right)\\
pthh:4Al+3O_2\underrightarrow{t^o}2Al_2O_3\)
0,1 0,05
=> \(m_{Al_2O_3}=102.0,05=5,1\left(g\right)\)
\(n_{Al}=\dfrac{2,7}{27}=0,1\left(mol\right)\)
PTHH: 4Al + 3O2 --to--> 2Al2O3
0,1------------------>0,05
=> mAl2O3 = 0,05.102 = 5,1 (g)